Commit Graph

236 Commits

Author SHA1 Message Date
Avi Kivity
35cc7f9711 KVM: Fold drivers/kvm/kvm_vmx.h into drivers/kvm/vmx.c
No meat in that file.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:30 +03:00
Avi Kivity
e38aea3e93 KVM: VMX: Don't switch 64-bit msrs for 32-bit guests
Some msrs are only used by x86_64 instructions, and are therefore
not needed when the guest is legacy mode.  By not bothering to switch
them, we reduce vmexit latency by 2400 cycles (from about 8800) when
running a 32-bt guest on a 64-bit host.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:30 +03:00
Avi Kivity
2345df8c55 KVM: VMX: Reduce unnecessary saving of host msrs
THe automatically switched msrs are never changed on the host (with
the exception of MSR_KERNEL_GS_BASE) and thus there is no need to save
them on every vm entry.

This reduces vmexit latency by ~400 cycles on i386 and by ~900 cycles (10%)
on x86_64.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
c9047f5333 KVM: Handle guest page faults when emulating mmio
Usually, guest page faults are detected by the kvm page fault handler,
which detects if they are shadow faults, mmio faults, pagetable faults,
or normal guest page faults.

However, in ceratin circumstances, we can detect a page fault much later.
One of these events is the following combination:

- A two memory operand instruction (e.g. movsb) is executed.
- The first operand is in mmio space (which is the fault reported to kvm)
- The second operand is in an ummaped address (e.g. a guest page fault)

The Windows 2000 installer does such an access, an promptly hangs.  Fix
by adding the missing page fault injection on that path.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
364b625b56 KVM: SVM: Report hardware exit reason to userspace instead of dmesg
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
8c4385024d KVM: Retry sleeping allocation if atomic allocation fails
This avoids -ENOMEM under memory pressure.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
b5a33a7572 KVM: Use slab caches to allocate mmu data structures
Better leak detection, statistics, memory use, speed -- goodness all
around.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
417726a3fb KVM: Handle partial pae pdptr
Some guests (Solaris) do not set up all four pdptrs, but leave some invalid.
kvm incorrectly treated these as valid page directories, pinning the
wrong pages and causing general confusion.

Fix by checking the valid bit of a pae pdpte.  This closes sourceforge bug
1698922.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
d917a6b92d KVM: Initialize cr0 to indicate an fpu is present
Solaris panics if it sees a cpu with no fpu, and it seems to rely on this
bit.  Closes sourceforge bug 1698920.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Eric Sesterhenn / Snakebyte
3964994bb5 KVM: Fix overflow bug in overflow detection code
The expression

   sp - 6 < sp

where sp is a u16 is undefined in C since 'sp - 6' is promoted to int,
and signed overflow is undefined in C.  gcc 4.2 actually warns about it.
Replace with a simpler test.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:29 +03:00
Avi Kivity
5008fdf5b6 KVM: Use kernel-standard types
Noted by Joerg Roedel.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Joerg Roedel
80b7706e4c KVM: SVM: enable LBRV virtualization if available
This patch enables the virtualization of the last branch record MSRs on
SVM if this feature is available in hardware. It also introduces a small
and simple check feature for specific SVM extensions.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Avi Kivity
b8836737d9 KVM: Add fpu get/set operations
These are really helpful when migrating an floating point app to another
machine.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Avi Kivity
e8207547d2 KVM: Add physical memory aliasing feature
With this, we can specify that accesses to one physical memory range will
be remapped to another.  This is useful for the vga window at 0xa0000 which
is used as a movable window into the (much larger) framebuffer.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Avi Kivity
954bbbc236 KVM: Simply gfn_to_page()
Mapping a guest page to a host page is a common operation.  Currently,
one has first to find the memory slot where the page belongs (gfn_to_memslot),
then locate the page itself (gfn_to_page()).

This is clumsy, and also won't work well with memory aliases.  So simplify
gfn_to_page() not to require memory slot translation first, and instead do it
internally.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Dor Laor
e0fa826f96 KVM: Add mmu cache clear function
Functions that play around with the physical memory map
need a way to clear mappings to possibly nonexistent or
invalid memory.  Both the mmu cache and the processor tlb
are cleared.

Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Avi Kivity
df513e2cdd KVM: x86 emulator: fix bit string operations operand size
On x86, bit operations operate on a string of bits that can reside in
multiple words.  For example, 'btsl %eax, (blah)' will touch the word
at blah+4 if %eax is between 32 and 63.

The x86 emulator compensates for that by advancing the operand address
by (bit offset / BITS_PER_LONG) and truncating the bit offset to the
range (0..BITS_PER_LONG-1).  This has a side effect of forcing the operand
size to 8 bytes on 64-bit hosts.

Now, a 32-bit guest goes and fork()s a process.  It write protects a stack
page at 0xbffff000 using the 'btr' instruction, at offset 0xffc in the page
table, with bit offset 1 (for the write permission bit).

The emulator now forces the operand size to 8 bytes as previously described,
and an innocent page table update turns into a cross-page-boundary write,
which is assumed by the mmu code not to be a page table, so it doesn't
actually clear the corresponding shadow page table entry.  The guest and
host permissions are out of sync and guest memory is corrupted soon
afterwards, leading to guest failure.

Fix by not using BITS_PER_LONG as the word size; instead use the actual
operand size, so we get a 32-bit write in that case.

Note we still have to teach the mmu to handle cross-page-boundary writes
to guest page table; but for now this allows Damn Small Linux 0.4 (2.4.20)
to boot.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:28 +03:00
Avi Kivity
afeb1f14c5 KVM: Remove debug message
No longer interesting.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:27 +03:00
Avi Kivity
36868f7b0e KVM: Use list_move()
Use list_move() where possible.  Noticed by Dor Laor.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:27 +03:00
Michal Piotrowski
55bf402834 KVM: Remove unused function
Remove unused function

CC      drivers/kvm/svm.o
drivers/kvm/svm.c:207: warning: ‘inject_db’ defined but not used

Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:27 +03:00
Avi Kivity
0cc5064d33 KVM: SVM: Ensure timestamp counter monotonicity
When a vcpu is migrated from one cpu to another, its timestamp counter
may lose its monotonic property if the host has unsynced timestamp counters.
This can confuse the guest, sometimes to the point of refusing to boot.

As the rdtsc instruction is rather fast on AMD processors (7-10 cycles),
we can simply record the last host tsc when we drop the cpu, and adjust
the vcpu tsc offset when we detect that we've migrated to a different cpu.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:27 +03:00
Avi Kivity
d28c6cfbbc KVM: MMU: Fix hugepage pdes mapping same physical address with different access
The kvm mmu keeps a shadow page for hugepage pdes; if several such pdes map
the same physical address, they share the same shadow page.  This is a fairly
common case (kernel mappings on i386 nonpae Linux, for example).

However, if the two pdes map the same memory but with different permissions, kvm
will happily use the cached shadow page.  If the access through the more
permissive pde will occur after the access to the strict pde, an endless pagefault
loop will be generated and the guest will make no progress.

Fix by making the access permissions part of the cache lookup key.

The fix allows Xen pae to boot on kvm and run guest domains.

Thanks to Jeremy Fitzhardinge for reporting the bug and testing the fix.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:27 +03:00
Joerg Roedel
916ce2360f KVM: SVM: forbid guest to execute monitor/mwait
This patch forbids the guest to execute monitor/mwait instructions on
SVM. This is necessary because the guest can execute these instructions
if they are available even if the kvm cpuid doesn't report its
existence.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:26 +03:00
Sergey Kiselev
0e5bf0d0e4 KVM: Handle writes to MCG_STATUS msr
Some older (~2.6.7) kernels write MCG_STATUS register during kernel
boot (mce_clear_all() function, called from mce_init()). It's not
currently handled by kvm and will cause it to inject a GPF.
Following patch adds a "nop" handler for this.

Signed-off-by: Sergey Kiselev <sergey.kiselev@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:26 +03:00
Avi Kivity
fcd3410870 KVM: Remove unused and write-only variables
Trivial cleanup.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:26 +03:00
Avi Kivity
6da63cf95f KVM: Don't allow the guest to turn off the cpu cache
The cpu cache is a host resource; the guest should not be able to turn
it off (even for itself).

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:26 +03:00
Avi Kivity
038881c8be KVM: Hack real-mode segments on vmx from KVM_SET_SREGS
As usual, we need to mangle segment registers when emulating real mode
as vm86 has specific constraints.  We special case the reset segment base,
and set the "access rights" (or descriptor flags) to vm86 comaptible values.

This fixes reboot on vmx.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:26 +03:00
Avi Kivity
024aa1c02f KVM: Modify guest segments after potentially switching modes
The SET_SREGS ioctl modifies both cr0.pe (real mode/protected mode) and
guest segment registers.  Since segment handling is modified by the mode on
Intel procesors, update the segment registers after the mode switch has taken
place.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:26 +03:00
Avi Kivity
f6528b03f1 KVM: Remove set_cr0_no_modeswitch() arch op
set_cr0_no_modeswitch() was a hack to avoid corrupting segment registers.
As we now cache the protected mode values on entry to real mode, this
isn't an issue anymore, and it interferes with reboot (which usually _is_
a modeswitch).

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:25 +03:00
Avi Kivity
8cb5b03332 KVM: Workaround vmx inability to virtualize the reset state
The reset state has cs.selector == 0xf000 and cs.base == 0xffff0000,
which aren't compatible with vm86 mode, which is used for real mode
virtualization.

When we create a vcpu, we set cs.base to 0xf0000, but if we get there by
way of a reset, the values are inconsistent and vmx refuses to enter
guest mode.

Workaround by detecting the state and munging it appropriately.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:25 +03:00
Avi Kivity
aac012245a KVM: MMU: Remove global pte tracking
The initial, noncaching, version of the kvm mmu flushed the all nonglobal
shadow page table translations (much like a native tlb flush).  The new
implementation flushes translations only when they change, rendering global
pte tracking superfluous.

This removes the unused tracking mechanism and storage space.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:25 +03:00
Avi Kivity
ca5aac1f96 KVM: MMU: Remove unnecessary check for pdptr access
We already special case the pdptr access, so no need to check it again.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:25 +03:00
Avi Kivity
039576c03c KVM: Avoid guest virtual addresses in string pio userspace interface
The current string pio interface communicates using guest virtual addresses,
relying on userspace to translate addresses and to check permissions.  This
interface cannot fully support guest smp, as the check needs to take into
account two pages at one in case an unaligned string transfer straddles a
page boundary.

Change the interface not to communicate guest addresses at all; instead use
a buffer page (mmaped by userspace) and do transfers there.  The kernel
manages the virtual to physical translation and can perform the checks
atomically by taking the appropriate locks.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:25 +03:00
Avi Kivity
f0fe510864 KVM: Future-proof argument-less ioctls
Some ioctls ignore their arguments.  By requiring them to be zero now,
we allow a nonzero value to have some special meaning in the future.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:25 +03:00
Avi Kivity
07c45a366d KVM: Allow kernel to select size of mmap() buffer
This allows us to store offsets in the kernel/user kvm_run area, and be
sure that userspace has them mapped.  As offsets can be outside the
kvm_run struct, userspace has no way of knowing how much to mmap.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
1961d276c8 KVM: Add guest mode signal mask
Allow a special signal mask to be used while executing in guest mode.  This
allows signals to be used to interrupt a vcpu without requiring signal
delivery to a userspace handler, which is quite expensive.  Userspace still
receives -EINTR and can get the signal via sigwait().

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
6722c51c51 KVM: Initialize the apic_base msr on svm too
Older userspace didn't care, but newer userspace (with the cpuid changes)
does.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
1b19f3e61d KVM: Add a special exit reason when exiting due to an interrupt
This is redundant, as we also return -EINTR from the ioctl, but it
allows us to examine the exit_reason field on resume without seeing
old data.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
8eb7d334bd KVM: Fold kvm_run::exit_type into kvm_run::exit_reason
Currently, userspace is told about the nature of the last exit from the
guest using two fields, exit_type and exit_reason, where exit_type has
just two enumerations (and no need for more).  So fold exit_type into
exit_reason, reducing the complexity of determining what really happened.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
b4e63f560b KVM: Allow userspace to process hypercalls which have no kernel handler
This is useful for paravirtualized graphics devices, for example.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
5d308f4550 KVM: Add method to check for backwards-compatible API extensions
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:24 +03:00
Avi Kivity
106b552b43 KVM: Remove the 'emulated' field from the userspace interface
We no longer emulate single instructions in userspace.  Instead, we service
mmio or pio requests.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:23 +03:00
Avi Kivity
06465c5a3a KVM: Handle cpuid in the kernel instead of punting to userspace
KVM used to handle cpuid by letting userspace decide what values to
return to the guest.  We now handle cpuid completely in the kernel.  We
still let userspace decide which values the guest will see by having
userspace set up the value table beforehand (this is necessary to allow
management software to set the cpu features to the least common denominator,
so that live migration can work).

The motivation for the change is that kvm kernel code can be impacted by
cpuid features, for example the x86 emulator.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:23 +03:00
Avi Kivity
46fc147788 KVM: Do not communicate to userspace through cpu registers during PIO
Currently when passing the a PIO emulation request to userspace, we
rely on userspace updating %rax (on 'in' instructions) and %rsi/%rdi/%rcx
(on string instructions).  This (a) requires two extra ioctls for getting
and setting the registers and (b) is unfriendly to non-x86 archs, when
they get kvm ports.

So fix by doing the register fixups in the kernel and passing to userspace
only an abstract description of the PIO to be done.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:23 +03:00
Avi Kivity
9a2bb7f486 KVM: Use a shared page for kernel/user communication when runing a vcpu
Instead of passing a 'struct kvm_run' back and forth between the kernel and
userspace, allocate a page and allow the user to mmap() it.  This reduces
needless copying and makes the interface expandable by providing lots of
free space.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:23 +03:00
Avi Kivity
1ea252afcd KVM: Fix bogus sign extension in mmu mapping audit
When auditing a 32-bit guest on a 64-bit host, sign extension of the page
table directory pointer table index caused bogus addresses to be shown on
audit errors.

Fix by declaring the index unsigned.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:23 +03:00
Avi Kivity
bbe4432e66 KVM: Use own minor number
Use the minor number (232) allocated to kvm by lanana.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:22 +03:00
Dor Laor
510043da85 KVM: Use the generic skip_emulated_instruction() in hypercall code
Instead of twiddling the rip registers directly, use the
skip_emulated_instruction() function to do that for us.

Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:22 +03:00
Dor Laor
9b22bf5783 KVM: Fix guest register corruption on paravirt hypercall
The hypercall code mixes up the ->cache_regs() and ->decache_regs()
callbacks, resulting in guest register corruption.

Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-03 10:52:22 +03:00
Avi Kivity
6b8d0f9b18 KVM: Fix off-by-one when writing to a nonpae guest pde
Nonpae guest pdes are shadowed by two pae ptes, so we double the offset
twice: once to account for the pte size difference, and once because we
need to shadow pdes for a single guest pde.

But when writing to the upper guest pde we also need to truncate the
lower bits, otherwise the multiply shifts these bits into the pde index
and causes an access to the wrong shadow pde.  If we're at the end of the
page (accessing the very last guest pde) we can even overflow into the
next host page and oops.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-04-19 18:39:26 +03:00
Ingo Molnar
6d9658df07 KVM: always reload segment selectors
failed VM entry on VMX might still change %fs or %gs, thus make sure
that KVM always reloads the segment selectors. This is crutial on both
x86 and x86_64: x86 has __KERNEL_PDA in %fs on which things like
'current' depends and x86_64 has 0 there and needs MSR_GS_BASE to work.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-03-27 17:55:48 +02:00
Avi Kivity
6af11b9e82 KVM: Prevent system selectors leaking into guest on real->protected mode transition on vmx
Intel virtualization extensions do not support virtualizing real mode.  So
kvm uses virtualized vm86 mode to run real mode code.  Unfortunately, this
virtualized vm86 mode does not support the so called "big real" mode, where
the segment selector and base do not agree with each other according to the
real mode rules (base == selector << 4).

To work around this, kvm checks whether a selector/base pair violates the
virtualized vm86 rules, and if so, forces it into conformance.  On a
transition back to protected mode, if we see that the guest did not touch
a forced segment, we restore it back to the original protected mode value.

This pile of hacks breaks down if the gdt has changed in real mode, as it
can cause a segment selector to point to a system descriptor instead of a
normal data segment.  In fact, this happens with the Windows bootloader
and the qemu acpi bios, where a protected mode memcpy routine issues an
innocent 'pop %es' and traps on an attempt to load a system descriptor.

"Fix" by checking if the to-be-restored selector points at a system segment,
and if so, coercing it into a normal data segment.  The long term solution,
of course, is to abandon vm86 mode and use emulation for big real mode.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-27 17:54:38 +02:00
Avi Kivity
27aba76615 KVM: MMU: Fix host memory corruption on i386 with >= 4GB ram
PAGE_MASK is an unsigned long, so using it to mask physical addresses on
i386 (which are 64-bit wide) leads to truncation.  This can result in
page->private of unrelated memory pages being modified, with disasterous
results.

Fix by not using PAGE_MASK for physical addresses; instead calculate
the correct value directly from PAGE_SIZE.  Also fix a similar BUG_ON().

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18 10:49:09 +02:00
Avi Kivity
ac1b714e78 KVM: MMU: Fix guest writes to nonpae pde
KVM shadow page tables are always in pae mode, regardless of the guest
setting.  This means that a guest pde (mapping 4MB of memory) is mapped
to two shadow pdes (mapping 2MB each).

When the guest writes to a pte or pde, we intercept the write and emulate it.
We also remove any shadowed mappings corresponding to the write.  Since the
mmu did not account for the doubling in the number of pdes, it removed the
wrong entry, resulting in a mismatch between shadow page tables and guest
page tables, followed shortly by guest memory corruption.

This patch fixes the problem by detecting the special case of writing to
a non-pae pde and adjusting the address and number of shadow pdes zapped
accordingly.

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18 10:49:09 +02:00
Avi Kivity
f5b42c3324 KVM: Fix guest sysenter on vmx
The vmx code currently treats the guest's sysenter support msrs as 32-bit
values, which breaks 32-bit compat mode userspace on 64-bit guests.  Fix by
using the native word width of the machine.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18 10:49:06 +02:00
Avi Kivity
ca45aaae1e KVM: Unset kvm_arch_ops if arch module loading failed
Otherwise, the core module thinks the arch module is loaded, and won't
let you reload it after you've fixed the bug.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-18 10:49:06 +02:00
Andrew Morton
e9cdb1e330 KVM: Move kvmfs magic number to <linux/magic.h>
Use the standard magic.h for kvmfs.

Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:43 +02:00
Avi Kivity
58e690e6fd KVM: Fix bogus failure in kvm.ko module initialization
A bogus 'return r' can cause an otherwise successful module load to fail.
This both denies users the use of kvm, and it also denies them the use of
their machine, as it leaves a filesystem registered with its callbacks
pointing into now-freed module memory.

Fix by returning a zero like a good module.

Thanks to Richard Lucassen <mailinglists@lucassen.org> (?) for reporting
the problem and for providing access to a machine which exhibited it.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:43 +02:00
Uri Lublin
ff990d5952 KVM: Remove write access permissions when dirty-page-logging is enabled
Enabling dirty page logging is done using KVM_SET_MEMORY_REGION ioctl.
If the memory region already exists, we need to remove write accesses,
so writes will be caught, and dirty pages will be logged.

Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:43 +02:00
Uri Lublin
02b27c1f80 kvm: move do_remove_write_access() up
To be called from kvm_vm_ioctl_set_memory_region()

Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:43 +02:00
Uri Lublin
cd1a4a982a KVM: Fix dirty page log bitmap size/access calculation
Since dirty_bitmap is an unsigned long array, the alignment and size need
to take that into account.

Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:42 +02:00
Uri Lublin
ab51a434c5 KVM: Add missing calls to mark_page_dirty()
A few places where we modify guest memory fail to call mark_page_dirty(),
causing live migration to fail.  This adds the missing calls.

Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:42 +02:00
Avi Kivity
bccf2150fe KVM: Per-vcpu inodes
Allocate a distinct inode for every vcpu in a VM.  This has the following
benefits:

 - the filp cachelines are no longer bounced when f_count is incremented on
   every ioctl()
 - the API and internal code are distinctly clearer; for example, on the
   KVM_GET_REGS ioctl, there is no need to copy the vcpu number from
   userspace and then copy the registers back; the vcpu identity is derived
   from the fd used to make the call

Right now the performance benefits are completely theoretical since (a) we
don't support more than one vcpu per VM and (b) virtualization hardware
inefficiencies completely everwhelm any cacheline bouncing effects.  But
both of these will change, and we need to prepare the API today.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:42 +02:00
Avi Kivity
c5ea766006 KVM: Move kvm_vm_ioctl_create_vcpu() around
In preparation of some hacking.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:42 +02:00
Avi Kivity
2c6f5df979 KVM: Rename some kvm_dev_ioctl_*() functions to kvm_vm_ioctl_*()
This reflects the changed scope, from device-wide to single vm (previously
every device open created a virtual machine).

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:42 +02:00
Avi Kivity
f17abe9a44 KVM: Create an inode per virtual machine
This avoids having filp->f_op and the corresponding inode->i_fop different,
which is a little unorthodox.

The ioctl list is split into two: global kvm ioctls and per-vm ioctls.  A new
ioctl, KVM_CREATE_VM, is used to create VMs and return the VM fd.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:42 +02:00
Avi Kivity
37e29d906c KVM: Add internal filesystem for generating inodes
The kvmfs inodes will represent virtual machines and vcpus, as necessary,
reducing cacheline bouncing due to inodes and filps being shared.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:41 +02:00
Avi Kivity
19d1408dfd KVM: More 0 -> NULL conversions
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:41 +02:00
Joerg Roedel
0152527b76 KVM: SVM: intercept SMI to handle it at host level
This patch changes the SVM code to intercept SMIs and handle it
outside the guest.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:41 +02:00
Avi Kivity
cd205625e9 KVM: svm: init cr0 with the wp bit set
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:41 +02:00
Avi Kivity
270fd9b96f KVM: Wire up hypercall handlers to a central arch-independent location
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:41 +02:00
Avi Kivity
02e235bc8e KVM: Add hypercall host support for svm
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:41 +02:00
Ingo Molnar
c21415e843 KVM: Add host hypercall support for vmx
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:40 +02:00
Ingo Molnar
102d8325a1 KVM: add MSR based hypercall API
This adds a special MSR based hypercall API to KVM. This is to be
used by paravirtual kernels and virtual drivers.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:40 +02:00
Markus Rechberger
5972e9535e KVM: Use page_private()/set_page_private() apis
Besides using an established api, this allows using kvm in older kernels.

Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:39 +02:00
Ahmed S. Darwish
9d8f549dc6 KVM: Use ARRAY_SIZE macro instead of manual calculation.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:39 +02:00
Joerg Roedel
de979caacc KVM: vmx: hack set_cr0_no_modeswitch() to actually do modeswitch
The whole thing is rotten, but this allows vmx to boot with the guest reboot
fix.

Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:39 +02:00
Avi Kivity
d27d4aca18 KVM: Cosmetics
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:39 +02:00
Jeremy Katz
43934a38d7 KVM: Move virtualization deactivation from CPU_DEAD state to CPU_DOWN_PREPARE
This gives it more chances of surviving suspend.

Signed-off-by: Jeremy Katz <katzj@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:39 +02:00
Avi Kivity
bf3f8e86c2 KVM: mmu: add missing dirty page tracking cases
We fail to mark a page dirty in three cases:

- setting the accessed bit in a pte
- setting the dirty bit in a pte
- emulating a write into a pagetable

This fix adds the missing cases.

Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04 11:12:39 +02:00
Jeremy Fitzhardinge
464d1a78fb [PATCH] i386: Convert i386 PDA code to use %fs
Convert the PDA code to use %fs rather than %gs as the segment for
per-processor data.  This is because some processors show a small but
measurable performance gain for reloading a NULL segment selector (as %fs
generally is in user-space) versus a non-NULL one (as %gs generally is).

On modern processors the difference is very small, perhaps undetectable.
Some old AMD "K6 3D+" processors are noticably slower when %fs is used
rather than %gs; I have no idea why this might be, but I think they're
sufficiently rare that it doesn't matter much.

This patch also fixes the math emulator, which had not been adjusted to
match the changed struct pt_regs.

[frederik.deweerdt@gmail.com: fixit with gdb]
[mingo@elte.hu: Fix KVM too]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Ian Campbell <Ian.Campbell@XenSource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Zachary Amsden <zach@vmware.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-13 13:26:20 +01:00
Avi Kivity
59ae6c6b87 [PATCH] KVM: Host suspend/resume support
Add the necessary callbacks to suspend and resume a host running kvm.  This is
just a repeat of the cpu hotplug/unplug work.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:41 -08:00
Avi Kivity
774c47f1d7 [PATCH] KVM: cpu hotplug support
On hotplug, we execute the hardware extension enable sequence.  On unplug, we
decache any vcpus that last ran on the exiting cpu, and execute the hardware
extension disable sequence.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:41 -08:00
Avi Kivity
8d0be2b3bf [PATCH] KVM: VMX: add vcpu_clear()
Like the inline code it replaces, this function decaches the vmcs from the cpu
it last executed on.  in addition:

 - vcpu_clear() works if the last cpu is also the cpu we're running on
 - it is faster on larger smps by virtue of using smp_call_function_single()

Includes fix from Ingo Molnar.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:41 -08:00
Avi Kivity
133de9021d [PATCH] KVM: Add a global list of all virtual machines
This will allow us to iterate over all vcpus and see which cpus they are
running on.

[akpm@osdl.org: use standard (ugly) initialisers]
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Ingo Molnar
1e8ba6fba5 [PATCH] kvm: fix vcpu freeing bug
vcpu_load() can return NULL and it sometimes does in failure paths (for
example when the userspace ABI version is too old) - causing a preemption
count underflow in the ->vcpu_free() later on.  So check for NULL.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Avi Kivity
26bb83a755 [PATCH] kvm: VMX: Reload ds and es even in 64-bit mode
Or 32-bit userspace will get confused.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Dor Laor
54810342f1 [PATCH] kvm: Two-way apic tpr synchronization
We report the value of cr8 to userspace on an exit.  Also let userspace change
cr8 when we re-enter the guest.  The lets 64-bit guest code maintain the tpr
correctly.

Thanks for Yaniv Kamay for the idea.

Signed-off-by: Dor Laor <dor.laor@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Avi Kivity
d92899a001 [PATCH] kvm: SVM: Hack initial cpu csbase to be consistent with intel
This allows us to run the mmu testsuite on amd.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Avi Kivity
ac6c2bc592 [PATCH] kvm: Fix mmu going crazy of guest sets cr0.wp == 0
The kvm mmu relies on cr0.wp being set even if the guest does not set it.  The
vmx code correctly forces cr0.wp at all times, the svm code does not, so it
can't boot solaris without this patch.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Avi Kivity
988ad74ff6 [PATCH] kvm: vmx: handle triple faults by returning EXIT_REASON_SHUTDOWN to userspace
Just like svm.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Avi Kivity
e119d117a1 [PATCH] kvm: Fix gva_to_gpa()
gva_to_gpa() needs to be updated to the new walk_addr() calling convention,
otherwise it may oops under some circumstances.

Use the opportunity to remove all the code duplication in gva_to_gpa(), which
essentially repeats the calculations in walk_addr().

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
S.Caglar Onur
a0610ddf6b [PATCH] kvm: Fix asm constraint for lldt instruction
lldt does not accept immediate operands, which "g" allows.

Signed-off-by: S.Caglar Onur <caglar@pardus.org.tr>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Ingo Molnar
96958231ce [PATCH] kvm: optimize inline assembly
Forms like "0(%rsp)" generate an instruction with an unnecessary one byte
displacement under certain circumstances.  replace with the equivalent
"(%rsp)".

Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:40 -08:00
Al Viro
11718b4d6b [PATCH] misc NULL noise removal
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09 09:14:07 -08:00
Al Viro
8b6d44c7bd [PATCH] kvm: NULL noise removal
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09 09:14:07 -08:00
Al Viro
2f36698799 [PATCH] kvm: __user annotations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09 09:14:07 -08:00
Avi Kivity
432bd6cbf9 [PATCH] KVM: fix lockup on 32-bit intel hosts with nx disabled in the bios
Intel hosts, without long mode, and with nx support disabled in the bios
have an efer that is readable but not writable.  This causes a lockup on
switch to guest mode (even though it should exit with reason 34 according
to the documentation).

Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-01 16:22:41 -08:00
Robert P. J. Day
49b14f24cc [PATCH] Fix "CONFIG_X86_64_" typo in drivers/kvm/svm.c
Fix what looks like an obvious typo in the file drivers/kvm/svm.c.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-30 08:26:45 -08:00
Joerg Roedel
46fe4ddd9d [PATCH] KVM: SVM: Propagate cpu shutdown events to userspace
This patch implements forwarding of SHUTDOWN intercepts from the guest on to
userspace on AMD SVM.  A SHUTDOWN event occurs when the guest produces a
triple fault (e.g.  on reboot).  This also fixes the bug that a guest reboot
actually causes a host reboot under some circumstances.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26 13:50:57 -08:00