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linux/arch/powerpc/kvm/book3s_64_slb.S

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Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright SUSE Linux Products GmbH 2009
*
* Authors: Alexander Graf <agraf@suse.de>
*/
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
#define SHADOW_SLB_ENTRY_LEN 0x10
#define OFFSET_ESID(x) (SHADOW_SLB_ENTRY_LEN * x)
#define OFFSET_VSID(x) ((SHADOW_SLB_ENTRY_LEN * x) + 8)
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
.macro LOAD_GUEST_SEGMENTS
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/* Required state:
*
* MSR = ~IR|DR
* R13 = PACA
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 09:58:03 +08:00
* R1 = host R1
* R2 = host R2
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
* R3 = shadow vcpu
KVM: PPC: book3s_pr: Simplify transitions between virtual and real mode This simplifies the way that the book3s_pr makes the transition to real mode when entering the guest. We now call kvmppc_entry_trampoline (renamed from kvmppc_rmcall) in the base kernel using a normal function call instead of doing an indirect call through a pointer in the vcpu. If kvm is a module, the module loader takes care of generating a trampoline as it does for other calls to functions outside the module. kvmppc_entry_trampoline then disables interrupts and jumps to kvmppc_handler_trampoline_enter in real mode using an rfi[d]. That then uses the link register as the address to return to (potentially in module space) when the guest exits. This also simplifies the way that we call the Linux interrupt handler when we exit the guest due to an external, decrementer or performance monitor interrupt. Instead of turning on the MMU, then deciding that we need to call the Linux handler and turning the MMU back off again, we now go straight to the handler at the point where we would turn the MMU on. The handler will then return to the virtual-mode code (potentially in the module). Along the way, this moves the setting and clearing of the HID5 DCBZ32 bit into real-mode interrupts-off code, and also makes sure that we clear the MSR[RI] bit before loading values into SRR0/1. The net result is that we no longer need any code addresses to be stored in vcpu->arch. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 15:41:44 +08:00
* all other volatile GPRS = free except R4, R6
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
*/
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
BEGIN_FW_FTR_SECTION
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
/* Declare SLB shadow as 0 entries big */
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
ld r11, PACA_SLBSHADOWPTR(r13)
li r8, 0
stb r8, 3(r11)
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
END_FW_FTR_SECTION_IFSET(FW_FEATURE_LPAR)
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/* Flush SLB */
KVM: PPC: Book3S PR: Fix invalidation of SLB entry 0 on guest entry On entering a PR KVM guest, we invalidate the whole SLB before loading up the guest entries. We do this using an slbia instruction, which invalidates all entries except entry 0, followed by an slbie to invalidate entry 0. However, the slbie turns out to be ineffective in some circumstances (specifically when the host linear mapping uses 64k pages) because of errors in computing the parameter to the slbie. The result is that the guest kernel hangs very early in boot because it takes a DSI the first time it tries to access kernel data using a linear mapping address in real mode. Currently we construct bits 36 - 43 (big-endian numbering) of the slbie parameter by taking bits 56 - 63 of the SLB VSID doubleword. These bits for the tlbie are C (class, 1 bit), B (segment size, 2 bits) and 5 reserved bits. For the SLB VSID doubleword these are C (class, 1 bit), reserved (1 bit), LP (large page size, 2 bits), and 4 reserved bits. Thus we are not setting the B field correctly, and when LP = 01 as it is for 64k pages, we are setting a reserved bit. Rather than add more instructions to calculate the slbie parameter correctly, this takes a simpler approach, which is to set entry 0 to zeroes explicitly. Normally slbmte should not be used to invalidate an entry, since it doesn't invalidate the ERATs, but it is OK to use it to invalidate an entry if it is immediately followed by slbia, which does invalidate the ERATs. (This has been confirmed with the Power architects.) This approach takes fewer instructions and will work whatever the contents of entry 0. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-06-22 15:14:11 +08:00
li r10, 0
slbmte r10, r10
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
slbia
/* Fill SLB with our shadow */
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
lbz r12, SVCPU_SLB_MAX(r3)
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
mulli r12, r12, 16
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
addi r12, r12, SVCPU_SLB
add r12, r12, r3
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/* for (r11 = kvm_slb; r11 < kvm_slb + kvm_slb_size; r11+=slb_entry) */
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
li r11, SVCPU_SLB
add r11, r11, r3
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
slb_loop_enter:
ld r10, 0(r11)
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
andis. r9, r10, SLB_ESID_V@h
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
beq slb_loop_enter_skip
ld r9, 8(r11)
slbmte r9, r10
slb_loop_enter_skip:
addi r11, r11, 16
cmpd cr0, r11, r12
blt slb_loop_enter
slb_do_enter:
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
.endm
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/******************************************************************************
* *
* Exit code *
* *
*****************************************************************************/
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
.macro LOAD_HOST_SEGMENTS
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
/* Register usage at this point:
*
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
* R1 = host R1
* R2 = host R2
* R12 = exit handler id
* R13 = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
* SVCPU.* = guest *
* SVCPU[CR] = guest CR
* SVCPU[XER] = guest XER
* SVCPU[CTR] = guest CTR
* SVCPU[LR] = guest LR
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
*
*/
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
/* Remove all SLB entries that are in use. */
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
KVM: PPC: Book3S PR: Use SLB entry 0 We didn't make use of SLB entry 0 because ... of no good reason. SLB entry 0 will always be used by the Linux linear SLB entry, so the fact that slbia does not invalidate it doesn't matter as we overwrite SLB 0 on exit anyway. Just enable use of SLB entry 0 for our shadow SLB code. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:36:05 +08:00
li r0, r0
slbmte r0, r0
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
slbia
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
/* Restore bolted entries from the shadow */
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
ld r11, PACA_SLBSHADOWPTR(r13)
KVM: PPC: Book3S PR: Rework SLB switching code On LPAR guest systems Linux enables the shadow SLB to indicate to the hypervisor a number of SLB entries that always have to be available. Today we go through this shadow SLB and disable all ESID's valid bits. However, pHyp doesn't like this approach very much and honors us with fancy machine checks. Fortunately the shadow SLB descriptor also has an entry that indicates the number of valid entries following. During the lifetime of a guest we can just swap that value to 0 and don't have to worry about the SLB restoration magic. While we're touching the code, let's also make it more readable (get rid of rldicl), allow it to deal with a dynamic number of bolted SLB entries and only do shadow SLB swizzling on LPAR systems. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-15 20:38:03 +08:00
BEGIN_FW_FTR_SECTION
/* Declare SLB shadow as SLB_NUM_BOLTED entries big */
li r8, SLB_NUM_BOLTED
stb r8, 3(r11)
END_FW_FTR_SECTION_IFSET(FW_FEATURE_LPAR)
/* Manually load all entries from shadow SLB */
li r8, SLBSHADOW_SAVEAREA
li r7, SLBSHADOW_SAVEAREA + 8
.rept SLB_NUM_BOLTED
LDX_BE r10, r11, r8
cmpdi r10, 0
beq 1f
LDX_BE r9, r11, r7
slbmte r9, r10
1: addi r7, r7, SHADOW_SLB_ENTRY_LEN
addi r8, r8, SHADOW_SLB_ENTRY_LEN
.endr
isync
sync
Add SLB switching code for entry/exit This is the really low level of guest entry/exit code. Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're currently aware of. The segments in the guest differ from the ones on the host, so we need to switch the SLB to tell the MMU that we're in a new context. So we store a shadow of the guest's SLB in the PACA, switch to that on entry and only restore bolted entries on exit, leaving the rest to the Linux SLB fault handler. That way we get a really clean way of switching the SLB. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-02 20:02:29 +08:00
slb_do_exit:
KVM: PPC: Make SLB switching code the new segment framework We just introduced generic segment switching code that only needs to call small macros to do the actual switching, but keeps most of the entry / exit code generic. So let's move the SLB switching code over to use this new mechanism. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-16 06:11:48 +08:00
.endm
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