One defense against L1TF in KVM is to always set the upper five bits
of the *legal* physical address in the SPTEs for non-present and
reserved SPTEs, e.g. MMIO SPTEs. In the MMIO case, the GFN of the
MMIO SPTE may overlap with the upper five bits that are being usurped
to defend against L1TF. To preserve the GFN, the bits of the GFN that
overlap with the repurposed bits are shifted left into the reserved
bits, i.e. the GFN in the SPTE will be split into high and low parts.
When retrieving the GFN from the MMIO SPTE, e.g. to check for an MMIO
access, get_mmio_spte_gfn() unshifts the affected bits and restores
the original GFN for comparison. Unfortunately, get_mmio_spte_gfn()
neglects to mask off the reserved bits in the SPTE that were used to
store the upper chunk of the GFN. As a result, KVM fails to detect
MMIO accesses whose GPA overlaps the repurprosed bits, which in turn
causes guest panics and hangs.
Fix the bug by generating a mask that covers the lower chunk of the
GFN, i.e. the bits that aren't shifted by the L1TF mitigation. The
alternative approach would be to explicitly zero the five reserved
bits that are used to store the upper chunk of the GFN, but that
requires additional run-time computation and makes an already-ugly
bit of code even more inscrutable.
I considered adding a WARN_ON_ONCE(low_phys_bits-1 <= PAGE_SHIFT) to
warn if GENMASK_ULL() generated a nonsensical value, but that seemed
silly since that would mean a system that supports VMX has less than
18 bits of physical address space...
Reported-by: Sakari Ailus <sakari.ailus@iki.fi>
Fixes: d9b47449c1 ("kvm: x86: Set highest physical address bits in non-present/reserved SPTEs")
Cc: Junaid Shahid <junaids@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Junaid Shahid <junaids@google.com>
Tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We currently display the default number of decimal places for floats in
_show_set_update_interval(), which is quite pointless. Cutting down to a
single decimal place.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
L2 IA32_BNDCFGS should be updated with vmcs12->guest_bndcfgs only
when VM_ENTRY_LOAD_BNDCFGS is specified in vmcs12->vm_entry_controls.
Otherwise, L2 IA32_BNDCFGS should be set to vmcs01->guest_bndcfgs which
is L1 IA32_BNDCFGS.
Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit a87036add0 ("KVM: x86: disable MPX if host did not enable
MPX XSAVE features") introduced kvm_mpx_supported() to return true
iff MPX is enabled in the host.
However, that commit seems to have missed replacing some calls to
kvm_x86_ops->mpx_supported() to kvm_mpx_supported().
Complete original commit by replacing remaining calls to
kvm_mpx_supported().
Fixes: a87036add0 ("KVM: x86: disable MPX if host did not enable
MPX XSAVE features")
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Before this commit, KVM exposes MPX VMX controls to L1 guest only based
on if KVM and host processor supports MPX virtualization.
However, these controls should be exposed to guest only in case guest
vCPU supports MPX.
Without this change, a L1 guest running with kernel which don't have
commit 691bd4340b ("kvm: vmx: allow host to access guest
MSR_IA32_BNDCFGS") asserts in QEMU on the following:
qemu-kvm: error: failed to set MSR 0xd90 to 0x0
qemu-kvm: .../qemu-2.10.0/target/i386/kvm.c:1801 kvm_put_msrs:
Assertion 'ret == cpu->kvm_msr_buf->nmsrs failed'
This is because L1 KVM kvm_init_msr_list() will see that
vmx_mpx_supported() (As it only checks MPX VMX controls support) and
therefore KVM_GET_MSR_INDEX_LIST IOCTL will include MSR_IA32_BNDCFGS.
However, later when L1 will attempt to set this MSR via KVM_SET_MSRS
IOCTL, it will fail because !guest_cpuid_has_mpx(vcpu).
Therefore, fix the issue by exposing MPX VMX controls to L1 guest only
when vCPU supports MPX.
Fixes: 36be0b9deb ("KVM: x86: Add nested virtualization support for MPX")
Reported-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Right now we temporarily take the page table lock in
gmap_pmd_op_walk() even though we know we won't need it (if we can
never have 1mb pages mapped into the gmap).
Let's make this a special case, so gmap_protect_range() and
gmap_sync_dirty_log_pmd() will not take the lock when huge pages are
not allowed.
gmap_protect_range() is called quite frequently for managing shadow
page tables in vSIE environments.
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20180806155407.15252-1-david@redhat.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
A host program identifier (HPID) provides information regarding the
underlying host environment. A level-2 (VM) guest will have an HPID
denoting Linux/KVM, which is set during VCPU setup. A level-3 (VM on a
VM) and beyond guest will have an HPID denoting KVM vSIE, which is set
for all shadow control blocks, overriding the original value of the
HPID.
Signed-off-by: Collin Walling <walling@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <1535734279-10204-4-git-send-email-walling@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch provides documentation describing the AP architecture and
design concepts behind the virtualization of AP devices. It also
includes an example of how to configure AP devices for exclusive
use of KVM guests.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Message-Id: <20180925231641.4954-27-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Introduces two new CPU model facilities to support
AP virtualization for KVM guests:
1. AP Query Configuration Information (QCI) facility is installed.
This is indicated by setting facilities bit 12 for
the guest. The kernel will not enable this facility
for the guest if it is not set on the host.
If this facility is not set for the KVM guest, then only
APQNs with an APQI less than 16 will be used by a Linux
guest regardless of the matrix configuration for the virtual
machine. This is a limitation of the Linux AP bus.
2. AP Facilities Test facility (APFT) is installed.
This is indicated by setting facilities bit 15 for
the guest. The kernel will not enable this facility for
the guest if it is not set on the host.
If this facility is not set for the KVM guest, then no
AP devices will be available to the guest regardless of
the guest's matrix configuration for the virtual
machine. This is a limitation of the Linux AP bus.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-26-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Introduces two new VM crypto device attributes (KVM_S390_VM_CRYPTO)
to enable or disable AP instruction interpretation from userspace
via the KVM_SET_DEVICE_ATTR ioctl:
* The KVM_S390_VM_CRYPTO_ENABLE_APIE attribute enables hardware
interpretation of AP instructions executed on the guest.
* The KVM_S390_VM_CRYPTO_DISABLE_APIE attribute disables hardware
interpretation of AP instructions executed on the guest. In this
case the instructions will be intercepted and pass through to
the guest.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-25-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When the guest schedules a SIE with a FORMAT-0 CRYCB,
we are able to schedule it in the host with a FORMAT-2
CRYCB if the host uses FORMAT-2
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-24-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When the guest schedules a SIE with a CRYCB FORMAT-1 CRYCB,
we are able to schedule it in the host with a FORMAT-2 CRYCB
if the host uses FORMAT-2.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-23-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When the guest schedules a SIE with a FORMAT-0 CRYCB,
we are able to schedule it in the host with a FORMAT-1
CRYCB if the host uses FORMAT-1 or FORMAT-0.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-22-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When the host and the guest both use a FORMAT-0 CRYCB,
we copy the guest's FORMAT-0 APCB to a shadow CRYCB
for use by vSIE.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-21-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When the host and guest both use a FORMAT-1 CRYCB, we copy
the guest's FORMAT-0 APCB to a shadow CRYCB for use by
vSIE.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-20-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When the guest and the host both use CRYCB FORMAT-2,
we copy the guest's FORMAT-1 APCB to a FORMAT-1
shadow APCB.
This patch also cleans up the shadow_crycb() function.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-19-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The comment preceding the shadow_crycb function is
misleading, we effectively accept FORMAT2 CRYCB in the
guest.
When using FORMAT2 in the host we do not need to or with
FORMAT1.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180925231641.4954-18-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We need to handle the validity checks for the crycb, no matter what the
settings for the keywrappings are. So lets move the keywrapping checks
after we have done the validy checks.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180925231641.4954-17-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When we clear the Crypto Control Block (CRYCB) used by a guest
level 2, the vSIE shadow CRYCB for guest level 3 must be updated
before the guest uses it.
We achieve this by using the KVM_REQ_VSIE_RESTART synchronous
request for each vCPU belonging to the guest to force the reload
of the shadow CRYCB before rerunning the guest level 3.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Message-Id: <20180925231641.4954-16-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Implements the VFIO_DEVICE_RESET ioctl. This ioctl zeroizes
all of the AP queues assigned to the guest.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-15-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's call PAPQ(ZAPQ) to zeroize a queue for each queue configured
for a mediated matrix device when it is released.
Zeroizing a queue resets the queue, clears all pending
messages for the queue entries and disables adapter interruptions
associated with the queue.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-14-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Adds support for the VFIO_DEVICE_GET_INFO ioctl to the VFIO
AP Matrix device driver. This is a minimal implementation,
as vfio-ap does not use I/O regions.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-13-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Implements the open callback on the mediated matrix device.
The function registers a group notifier to receive notification
of the VFIO_GROUP_NOTIFY_SET_KVM event. When notified,
the vfio_ap device driver will get access to the guest's
kvm structure. The open callback must ensure that only one
mediated device shall be opened per guest.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-12-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Introduces a new KVM function to clear the APCB0 and APCB1 in the guest's
CRYCB. This effectively clears all bits of the APM, AQM and ADM masks
configured for the guest. The VCPUs are taken out of SIE to ensure the
VCPUs do not get out of sync.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-11-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Provides a sysfs interface to view the AP matrix configured for the
mediated matrix device.
The relevant sysfs structures are:
/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. matrix
To view the matrix configured for the mediated matrix device,
print the matrix file:
cat matrix
Below are examples of the output from the above command:
Example 1: Adapters and domains assigned
Assignments:
Adapters 5 and 6
Domains 4 and 71 (0x47)
Output
05.0004
05.0047
06.0004
06.0047
Examples 2: Only adapters assigned
Assignments:
Adapters 5 and 6
Output:
05.
06.
Examples 3: Only domains assigned
Assignments:
Domains 4 and 71 (0x47)
Output:
.0004
.0047
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-10-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Provides the sysfs interfaces for:
1. Assigning AP control domains to the mediated matrix device
2. Unassigning AP control domains from a mediated matrix device
3. Displaying the control domains assigned to a mediated matrix
device
The IDs of the AP control domains assigned to the mediated matrix
device are stored in an AP domain mask (ADM). The bits in the ADM,
from most significant to least significant bit, correspond to
AP domain numbers 0 to 255. On some systems, the maximum allowable
domain number may be less than 255 - depending upon the host's
AP configuration - and assignment may be rejected if the input
domain ID exceeds the limit.
When a control domain is assigned, the bit corresponding its domain
ID will be set in the ADM. Likewise, when a domain is unassigned,
the bit corresponding to its domain ID will be cleared in the ADM.
The relevant sysfs structures are:
/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. assign_control_domain
.................. unassign_control_domain
To assign a control domain to the $uuid mediated matrix device's
ADM, write its domain number to the assign_control_domain file.
To unassign a domain, write its domain number to the
unassign_control_domain file. The domain number is specified
using conventional semantics: If it begins with 0x the number
will be parsed as a hexadecimal (case insensitive) number;
if it begins with 0, it is parsed as an octal number;
otherwise, it will be parsed as a decimal number.
For example, to assign control domain 173 (0xad) to the mediated
matrix device $uuid:
echo 173 > assign_control_domain
or
echo 0255 > assign_control_domain
or
echo 0xad > assign_control_domain
To unassign control domain 173 (0xad):
echo 173 > unassign_control_domain
or
echo 0255 > unassign_control_domain
or
echo 0xad > unassign_control_domain
The assignment will be rejected if the APQI exceeds the maximum
value for an AP domain:
* If the AP Extended Addressing (APXA) facility is installed,
the max value is 255
* Else the max value is 15
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-9-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Introduces two new sysfs attributes for the VFIO mediated
matrix device for assigning AP domains to and unassigning
AP domains from a mediated matrix device. The IDs of the
AP domains assigned to the mediated matrix device will be
stored in an AP queue mask (AQM).
The bits in the AQM, from most significant to least
significant bit, correspond to AP queue index (APQI) 0 to
255 (note that an APQI is synonymous with with a domain ID).
On some systems, the maximum allowable domain number may be
less than 255 - depending upon the host's AP configuration -
and assignment may be rejected if the input domain ID exceeds
the limit.
When a domain is assigned, the bit corresponding to the APQI
will be set in the AQM. Likewise, when a domain is unassigned,
the bit corresponding to the APQI will be cleared from the AQM.
In order to successfully assign a domain, the APQNs derived from
the domain ID being assigned and the adapter numbers of all
adapters previously assigned:
1. Must be bound to the vfio_ap device driver.
2. Must not be assigned to any other mediated matrix device.
If there are no adapters assigned to the mdev, then there must
be an AP queue bound to the vfio_ap device driver with an
APQN containing the domain ID (i.e., APQI), otherwise all
adapters subsequently assigned will fail because there will be no
AP queues bound with an APQN containing the APQI.
Assigning or un-assigning an AP domain will also be rejected if
a guest using the mediated matrix device is running.
The relevant sysfs structures are:
/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. assign_domain
.................. unassign_domain
To assign a domain to the $uuid mediated matrix device,
write the domain's ID to the assign_domain file. To
unassign a domain, write the domain's ID to the
unassign_domain file. The ID is specified using
conventional semantics: If it begins with 0x, the number
will be parsed as a hexadecimal (case insensitive) number;
if it begins with 0, it will be parsed as an octal number;
otherwise, it will be parsed as a decimal number.
For example, to assign domain 173 (0xad) to the mediated matrix
device $uuid:
echo 173 > assign_domain
or
echo 0255 > assign_domain
or
echo 0xad > assign_domain
To unassign domain 173 (0xad):
echo 173 > unassign_domain
or
echo 0255 > unassign_domain
or
echo 0xad > unassign_domain
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-8-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Introduces two new sysfs attributes for the VFIO mediated
matrix device for assigning AP adapters to and unassigning
AP adapters from a mediated matrix device. The IDs of the
AP adapters assigned to the mediated matrix device will be
stored in an AP mask (APM).
The bits in the APM, from most significant to least significant
bit, correspond to AP adapter IDs (APID) 0 to 255. On
some systems, the maximum allowable adapter number may be less
than 255 - depending upon the host's AP configuration - and
assignment may be rejected if the input adapter ID exceeds the
limit.
When an adapter is assigned, the bit corresponding to the APID
will be set in the APM. Likewise, when an adapter is
unassigned, the bit corresponding to the APID will be cleared
from the APM.
In order to successfully assign an adapter, the APQNs derived from
the adapter ID being assigned and the queue indexes of all domains
previously assigned:
1. Must be bound to the vfio_ap device driver.
2. Must not be assigned to any other mediated matrix device
If there are no domains assigned to the mdev, then there must
be an AP queue bound to the vfio_ap device driver with an
APQN containing the APID, otherwise all domains
subsequently assigned will fail because there will be no
AP queues bound with an APQN containing the adapter ID.
Assigning or un-assigning an AP adapter will be rejected if
a guest using the mediated matrix device is running.
The relevant sysfs structures are:
/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. assign_adapter
.................. unassign_adapter
To assign an adapter to the $uuid mediated matrix device's APM,
write the APID to the assign_adapter file. To unassign an adapter,
write the APID to the unassign_adapter file. The APID is specified
using conventional semantics: If it begins with 0x the number will
be parsed as a hexadecimal number; if it begins with a 0 the number
will be parsed as an octal number; otherwise, it will be parsed as a
decimal number.
For example, to assign adapter 173 (0xad) to the mediated matrix
device $uuid:
echo 173 > assign_adapter
or
echo 0xad > assign_adapter
or
echo 0255 > assign_adapter
To unassign adapter 173 (0xad):
echo 173 > unassign_adapter
or
echo 0xad > unassign_adapter
or
echo 0255 > unassign_adapter
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-7-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Registers the matrix device created by the VFIO AP device
driver with the VFIO mediated device framework.
Registering the matrix device will create the sysfs
structures needed to create mediated matrix devices
each of which will be used to configure the AP matrix
for a guest and connect it to the VFIO AP device driver.
Registering the matrix device with the VFIO mediated device
framework will create the following sysfs structures:
/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ create
To create a mediated device for the AP matrix device, write a UUID
to the create file:
uuidgen > create
A symbolic link to the mediated device's directory will be created in the
devices subdirectory named after the generated $uuid:
/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
............... [$uuid]
A symbolic link to the mediated device will also be created
in the vfio_ap matrix's directory:
/sys/devices/vfio_ap/matrix/[$uuid]
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <20180925231641.4954-6-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Introduces a new AP device driver. This device driver
is built on the VFIO mediated device framework. The framework
provides sysfs interfaces that facilitate passthrough
access by guests to devices installed on the linux host.
The VFIO AP device driver will serve two purposes:
1. Provide the interfaces to reserve AP devices for exclusive
use by KVM guests. This is accomplished by unbinding the
devices to be reserved for guest usage from the zcrypt
device driver and binding them to the VFIO AP device driver.
2. Implements the functions, callbacks and sysfs attribute
interfaces required to create one or more VFIO mediated
devices each of which will be used to configure the AP
matrix for a guest and serve as a file descriptor
for facilitating communication between QEMU and the
VFIO AP device driver.
When the VFIO AP device driver is initialized:
* It registers with the AP bus for control of type 10 (CEX4
and newer) AP queue devices. This limitation was imposed
due to:
1. A desire to keep the code as simple as possible;
2. Some older models are no longer supported by the kernel
and others are getting close to end of service.
3. A lack of older systems on which to test older devices.
The probe and remove callbacks will be provided to support
the binding/unbinding of AP queue devices to/from the VFIO
AP device driver.
* Creates a matrix device, /sys/devices/vfio_ap/matrix,
to serve as the parent of the mediated devices created, one
for each guest, and to hold the APQNs of the AP devices bound to
the VFIO AP device driver.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20180925231641.4954-5-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This patch refactors the code that initializes and sets up the
crypto configuration for a guest. The following changes are
implemented via this patch:
1. Introduces a flag indicating AP instructions executed on
the guest shall be interpreted by the firmware. This flag
is used to set a bit in the guest's state description
indicating AP instructions are to be interpreted.
2. Replace code implementing AP interfaces with code supplied
by the AP bus to query the AP configuration.
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <20180925231641.4954-4-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
When we change the crycb (or execution controls), we also have to make sure
that the vSIE shadow datastructures properly consider the changed
values before rerunning the vSIE. We can achieve that by simply using a
VCPU request now.
This has to be a synchronous request (== handled before entering the
(v)SIE again).
The request will make sure that the vSIE handler is left, and that the
request will be processed (NOP), therefore forcing a reload of all
vSIE data (including rebuilding the crycb) when re-entering the vSIE
interception handler the next time.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20180925231641.4954-3-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
VCPU requests and VCPU blocking right now don't take care of the vSIE
(as it was not necessary until now). But we want to have synchronous VCPU
requests that will also be handled before running the vSIE again.
So let's simulate a SIE entry of the VCPU when calling the sie during
vSIE handling and check for PROG_ flags. The existing infrastructure
(e.g. exit_sie()) will then detect that the SIE (in form of the vSIE) is
running and properly kick the vSIE CPU, resulting in it leaving the vSIE
loop and therefore the vSIE interception handler, allowing it to handle
VCPU requests.
E.g. if we want to modify the crycb of the VCPU and make sure that any
masks also get applied to the VSIE crycb shadow (which uses masks from the
VCPU crycb), we will need a way to hinder the vSIE from running and make
sure to process the updated crycb before reentering the vSIE again.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20180925231641.4954-2-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM has an old optimization whereby accesses to the kernel GS base MSR
are trapped when the guest is in 32-bit and not when it is in 64-bit mode.
The idea is that swapgs is not available in 32-bit mode, thus the
guest has no reason to access the MSR unless in 64-bit mode and
32-bit applications need not pay the price of switching the kernel GS
base between the host and the guest values.
However, this optimization adds complexity to the code for little
benefit (these days most guests are going to be 64-bit anyway) and in fact
broke after commit 678e315e78 ("KVM: vmx: add dedicated utility to
access guest's kernel_gs_base", 2018-08-06); the guest kernel GS base
can be corrupted across SMIs and UEFI Secure Boot is therefore broken
(a secure boot Linux guest, for example, fails to reach the login prompt
about half the time). This patch just removes the optimization; the
kernel GS base MSR is now never trapped by KVM, similarly to the FS and
GS base MSRs.
Fixes: 678e315e78
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
I swear I would have sent it the same to Linus! The main cause for
this is that I was on vacation until two weeks ago and it took a while
to sort all the pending patches between 4.19 and 4.20, test them and
so on.
It's mostly small bugfixes and cleanups, mostly around x86 nested
virtualization. One important change, not related to nested
virtualization, is that the ability for the guest kernel to trap CPUID
instructions (in Linux that's the ARCH_SET_CPUID arch_prctl) is now
masked by default. This is because the feature is detected through an
MSR; a very bad idea that Intel seems to like more and more. Some
applications choke if the other fields of that MSR are not initialized
as on real hardware, hence we have to disable the whole MSR by default,
as was the case before Linux 4.12.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Paolo writes:
"It's mostly small bugfixes and cleanups, mostly around x86 nested
virtualization. One important change, not related to nested
virtualization, is that the ability for the guest kernel to trap
CPUID instructions (in Linux that's the ARCH_SET_CPUID arch_prctl) is
now masked by default. This is because the feature is detected
through an MSR; a very bad idea that Intel seems to like more and
more. Some applications choke if the other fields of that MSR are
not initialized as on real hardware, hence we have to disable the
whole MSR by default, as was the case before Linux 4.12."
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (23 commits)
KVM: nVMX: Fix bad cleanup on error of get/set nested state IOCTLs
kvm: selftests: Add platform_info_test
KVM: x86: Control guest reads of MSR_PLATFORM_INFO
KVM: x86: Turbo bits in MSR_PLATFORM_INFO
nVMX x86: Check VPID value on vmentry of L2 guests
nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2
KVM: nVMX: Wake blocked vCPU in guest-mode if pending interrupt in virtual APICv
KVM: VMX: check nested state and CR4.VMXE against SMM
kvm: x86: make kvm_{load|put}_guest_fpu() static
x86/hyper-v: rename ipi_arg_{ex,non_ex} structures
KVM: VMX: use preemption timer to force immediate VMExit
KVM: VMX: modify preemption timer bit only when arming timer
KVM: VMX: immediately mark preemption timer expired only for zero value
KVM: SVM: Switch to bitmap_zalloc()
KVM/MMU: Fix comment in walk_shadow_page_lockless_end()
kvm: selftests: use -pthread instead of -lpthread
KVM: x86: don't reset root in kvm_mmu_setup()
kvm: mmu: Don't read PDPTEs when paging is not enabled
x86/kvm/lapic: always disable MMIO interface in x2APIC mode
KVM: s390: Make huge pages unavailable in ucontrol VMs
...
- A wrong UBIFS assertion in mount code
- Fix for a NULL pointer deref in mount code
- Revert of a bad fix for xattrs
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Merge tag 'upstream-4.19-rc4' of git://git.infradead.org/linux-ubifs
Richard writes:
"This pull request contains fixes for UBIFS:
- A wrong UBIFS assertion in mount code
- Fix for a NULL pointer deref in mount code
- Revert of a bad fix for xattrs"
* tag 'upstream-4.19-rc4' of git://git.infradead.org/linux-ubifs:
Revert "ubifs: xattr: Don't operate on deleted inodes"
ubifs: drop false positive assertion
ubifs: Check for name being NULL while mounting
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Merge tag 'for-linus-20180920' of git://git.kernel.dk/linux-block
Jens writes:
"Storage fixes for 4.19-rc5
- Fix for leaking kernel pointer in floppy ioctl (Andy Whitcroft)
- NVMe pull request from Christoph, and a single ANA log page fix
(Hannes)
- Regression fix for libata qd32 support, where we trigger an illegal
active command transition. This fixes a CD-ROM detection issue that
was reported, but could also trigger premature completion of the
internal tag (me)"
* tag 'for-linus-20180920' of git://git.kernel.dk/linux-block:
floppy: Do not copy a kernel pointer to user memory in FDGETPRM ioctl
libata: mask swap internal and hardware tag
nvme: count all ANA groups for ANA Log page
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Merge tag 'drm-fixes-2018-09-21' of git://anongit.freedesktop.org/drm/drm
David writes:
"drm fixes for 4.19-rc5:
- core: fix debugfs for atomic, fix the check for atomic for
non-modesetting drivers
- amdgpu: adds a new PCI id, some kfd fixes and a sdma fix
- i915: a bunch of GVT fixes.
- vc4: scaling fix
- vmwgfx: modesetting fixes and a old buffer eviction fix
- udl: framebuffer destruction fix
- sun4i: disable on R40 fix until next kernel
- pl111: NULL termination on table fix"
* tag 'drm-fixes-2018-09-21' of git://anongit.freedesktop.org/drm/drm: (21 commits)
drm/amdkfd: Fix ATS capablity was not reported correctly on some APUs
drm/amdkfd: Change the control stack MTYPE from UC to NC on GFX9
drm/amdgpu: Fix SDMA HQD destroy error on gfx_v7
drm/vmwgfx: Fix buffer object eviction
drm/vmwgfx: Don't impose STDU limits on framebuffer size
drm/vmwgfx: limit mode size for all display unit to texture_max
drm/vmwgfx: limit screen size to stdu_max during check_modeset
drm/vmwgfx: don't check for old_crtc_state enable status
drm/amdgpu: add new polaris pci id
drm: sun4i: drop second PLL from A64 HDMI PHY
drm: fix drm_drv_uses_atomic_modeset on non modesetting drivers.
drm/i915/gvt: clear ggtt entries when destroy vgpu
drm/i915/gvt: request srcu_read_lock before checking if one gfn is valid
drm/i915/gvt: Add GEN9_CLKGATE_DIS_4 to default BXT mmio handler
drm/i915/gvt: Init PHY related registers for BXT
drm/atomic: Use drm_drv_uses_atomic_modeset() for debugfs creation
drm/fb-helper: Remove set but not used variable 'connector_funcs'
drm: udl: Destroy framebuffer only if it was initialized
drm/sun4i: Remove R40 display pipeline compatibles
drm/pl111: Make sure of_device_id tables are NULL terminated
...
9092c71bb7 ("mm: use sc->priority for slab shrink targets") changed the
way that the target slab pressure is calculated and made it
priority-based:
delta = freeable >> priority;
delta *= 4;
do_div(delta, shrinker->seeks);
The problem is that on a default priority (which is 12) no pressure is
applied at all, if the number of potentially reclaimable objects is less
than 4096 (1<<12).
This causes the last objects on slab caches of no longer used cgroups to
(almost) never get reclaimed. It's obviously a waste of memory.
It can be especially painful, if these stale objects are holding a
reference to a dying cgroup. Slab LRU lists are reparented on memcg
offlining, but corresponding objects are still holding a reference to the
dying cgroup. If we don't scan these objects, the dying cgroup can't go
away. Most likely, the parent cgroup hasn't any directly charged objects,
only remaining objects from dying children cgroups. So it can easily hold
a reference to hundreds of dying cgroups.
If there are no big spikes in memory pressure, and new memory cgroups are
created and destroyed periodically, this causes the number of dying
cgroups grow steadily, causing a slow-ish and hard-to-detect memory
"leak". It's not a real leak, as the memory can be eventually reclaimed,
but it could not happen in a real life at all. I've seen hosts with a
steadily climbing number of dying cgroups, which doesn't show any signs of
a decline in months, despite the host is loaded with a production
workload.
It is an obvious waste of memory, and to prevent it, let's apply a minimal
pressure even on small shrinker lists. E.g. if there are freeable
objects, let's scan at least min(freeable, scan_batch) objects.
This fix significantly improves a chance of a dying cgroup to be
reclaimed, and together with some previous patches stops the steady growth
of the dying cgroups number on some of our hosts.
Link: http://lkml.kernel.org/r/20180905230759.12236-1-guro@fb.com
Fixes: 9092c71bb7 ("mm: use sc->priority for slab shrink targets")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Rik van Riel <riel@surriel.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'm' kcore_list item could point to kclist_head, and it is incorrect to
look at m->addr / m->size in this case.
There is no choice but to run through the list of entries for every
address if we did not find any entry in the previous iteration
Reset 'm' to NULL in that case at Omar Sandoval's suggestion.
[akpm@linux-foundation.org: add comment]
Link: http://lkml.kernel.org/r/1536100702-28706-1-git-send-email-asmadeus@codewreck.org
Fixes: bf991c2231 ("proc/kcore: optimize multiple page reads")
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Omar Sandoval <osandov@osandov.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: James Morse <james.morse@arm.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the clone and fork syscalls return EAGAIN when the limit on the
number of pids /proc/sys/kernel/pid_max is exceeded.
Currently, when the pid_max limit is exceeded, the kernel will return
ENOSPC from the fork and clone syscalls. This is contrary to the
documented behaviour, which explicitly calls out the pid_max case as one
where EAGAIN should be returned. It also leads to really confusing error
messages in userspace programs which will complain about a lack of disk
space when they fail to create processes/threads for this reason.
This error is being returned because alloc_pid() uses the idr api to find
a new pid; when there are none available, idr_alloc_cyclic() returns
-ENOSPC, and this is being propagated back to userspace.
This behaviour has been broken before, and was explicitly fixed in
commit 35f71bc0a0 ("fork: report pid reservation failure properly"),
so I think -EAGAIN is definitely the right thing to return in this case.
The current behaviour change dates from commit 95846ecf9d ("pid:
replace pid bitmap implementation with IDR AIP") and was I believe
unintentional.
This patch has no impact on the case where allocating a pid fails because
the child reaper for the namespace is dead; that case will still return
-ENOMEM.
Link: http://lkml.kernel.org/r/20180903111016.46461-1-ktsanaktsidis@zendesk.com
Fixes: 95846ecf9d ("pid: replace pid bitmap implementation with IDR AIP")
Signed-off-by: KJ Tsanaktsidis <ktsanaktsidis@zendesk.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Gargi Sharma <gs051095@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 11a6fc3dc7.
UBIFS wants to assert that xattr operations are only issued on files
with positive link count. The said patch made this operations return
-ENOENT for unlinked files such that the asserts will no longer trigger.
This was wrong since xattr operations are perfectly fine on unlinked
files.
Instead the assertions need to be fixed/removed.
Cc: <stable@vger.kernel.org>
Fixes: 11a6fc3dc7 ("ubifs: xattr: Don't operate on deleted inodes")
Reported-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Richard Weinberger <richard@nod.at>
The following sequence triggers
ubifs_assert(c, c->lst.taken_empty_lebs > 0);
at the end of ubifs_remount_fs():
mount -t ubifs /dev/ubi0_0 /mnt
echo 1 > /sys/kernel/debug/ubifs/ubi0_0/ro_error
umount /mnt
mount -t ubifs -o ro /dev/ubix_y /mnt
mount -o remount,ro /mnt
The resulting
UBIFS assert failed in ubifs_remount_fs at 1878 (pid 161)
is a false positive. In the case above c->lst.taken_empty_lebs has
never been changed from its initial zero value. This will only happen
when the deferred recovery is done.
Fix this by doing the assertion only when recovery has been done
already.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
