The patch titled
KVM: MMU: Fix cmpxchg8b emulation
has been added to the -mm tree. Its filename is
kvm-mmu-fix-cmpxchg8b-emulation.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: KVM: MMU: Fix cmpxchg8b emulation
From: Avi Kivity <avi@xxxxxxxxxxxx>
cmpxchg8b uses edx:eax as the compare operand, not edi:eax.
cmpxchg8b is used by 32-bit pae guests to set page table entries atomically,
and this is emulated touching shadowed guest page tables.
Also, implement it for 32-bit hosts.
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/kvm/kvm_main.c | 27 +++++++++++++++++++++++++++
drivers/kvm/x86_emulate.c | 2 +-
2 files changed, 28 insertions(+), 1 deletion(-)
diff -puN drivers/kvm/kvm_main.c~kvm-mmu-fix-cmpxchg8b-emulation drivers/kvm/kvm_main.c
--- a/drivers/kvm/kvm_main.c~kvm-mmu-fix-cmpxchg8b-emulation
+++ a/drivers/kvm/kvm_main.c
@@ -936,6 +936,30 @@ static int emulator_cmpxchg_emulated(uns
return emulator_write_emulated(addr, new, bytes, ctxt);
}
+#ifdef CONFIG_X86_32
+
+static int emulator_cmpxchg8b_emulated(unsigned long addr,
+ unsigned long old_lo,
+ unsigned long old_hi,
+ unsigned long new_lo,
+ unsigned long new_hi,
+ struct x86_emulate_ctxt *ctxt)
+{
+ static int reported;
+ int r;
+
+ if (!reported) {
+ reported = 1;
+ printk(KERN_WARNING "kvm: emulating exchange8b as write\n");
+ }
+ r = emulator_write_emulated(addr, new_lo, 4, ctxt);
+ if (r != X86EMUL_CONTINUE)
+ return r;
+ return emulator_write_emulated(addr+4, new_hi, 4, ctxt);
+}
+
+#endif
+
static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
return kvm_arch_ops->get_segment_base(vcpu, seg);
@@ -1010,6 +1034,9 @@ struct x86_emulate_ops emulate_ops = {
.read_emulated = emulator_read_emulated,
.write_emulated = emulator_write_emulated,
.cmpxchg_emulated = emulator_cmpxchg_emulated,
+#ifdef CONFIG_X86_32
+ .cmpxchg8b_emulated = emulator_cmpxchg8b_emulated,
+#endif
};
int emulate_instruction(struct kvm_vcpu *vcpu,
diff -puN drivers/kvm/x86_emulate.c~kvm-mmu-fix-cmpxchg8b-emulation drivers/kvm/x86_emulate.c
--- a/drivers/kvm/x86_emulate.c~kvm-mmu-fix-cmpxchg8b-emulation
+++ a/drivers/kvm/x86_emulate.c
@@ -1323,7 +1323,7 @@ twobyte_special_insn:
ctxt)) != 0))
goto done;
if ((old_lo != _regs[VCPU_REGS_RAX])
- || (old_hi != _regs[VCPU_REGS_RDI])) {
+ || (old_hi != _regs[VCPU_REGS_RDX])) {
_regs[VCPU_REGS_RAX] = old_lo;
_regs[VCPU_REGS_RDX] = old_hi;
_eflags &= ~EFLG_ZF;
_
Patches currently in -mm which might be from avi@xxxxxxxxxxxx are
kvm-fix-gfp_kernel-alloc-in-atomic-section-bug.patch
kvm-use-raw_smp_processor_id-instead-of-smp_processor_id-where-applicable.patch
kvm-recover-after-an-arch-module-load-failure.patch
kvm-improve-interrupt-response.patch
kvm-prevent-stale-bits-in-cr0-and-cr4.patch
kvm-mmu-implement-simple-reverse-mapping.patch
kvm-mmu-teach-the-page-table-walker-to-track-guest-page-table-gfns.patch
kvm-mmu-load-the-pae-pdptrs-on-cr3-change-like-the-processor-does.patch
kvm-mmu-fold-fetch_guest-into-init_walker.patch
kvm-mu-special-treatment-for-shadow-pae-root-pages.patch
kvm-mmu-use-the-guest-pdptrs-instead-of-mapping-cr3-in-pae-mode.patch
kvm-mmu-make-the-shadow-page-tables-also-special-case-pae.patch
kvm-mmu-make-kvm_mmu_alloc_page-return-a-kvm_mmu_page-pointer.patch
kvm-mmu-shadow-page-table-caching.patch
kvm-mmu-write-protect-guest-pages-when-a-shadow-is-created-for-them.patch
kvm-mmu-let-the-walker-extract-the-target-page-gfn-from-the-pte.patch
kvm-mmu-support-emulated-writes-into-ram.patch
kvm-mmu-zap-shadow-page-table-entries-on-writes-to-guest-page-tables.patch
kvm-mmu-if-emulating-an-instruction-fails-try-unprotecting-the-page.patch
kvm-mmu-implement-child-shadow-unlinking.patch
kvm-mmu-kvm_mmu_put_page-only-removes-one-link-to-the-page.patch
kvm-mmu-oom-handling.patch
kvm-mmu-remove-invlpg-interception.patch
kvm-mmu-remove-release_pt_page_64.patch
kvm-mmu-handle-misaligned-accesses-to-write-protected-guest-page-tables.patch
kvm-mmu-ove-is_empty_shadow_page-above-kvm_mmu_free_page.patch
kvm-mmu-ensure-freed-shadow-pages-are-clean.patch
kvm-mmu-if-an-empty-shadow-page-is-not-empty-report-more-info.patch
kvm-mmu-page-table-write-flood-protection.patch
kvm-mmu-never-free-a-shadow-page-actively-serving-as-a-root.patch
kvm-mmu-fix-cmpxchg8b-emulation.patch
kvm-mmu-treat-user-mode-faults-as-a-hint-that-a-page-is-no-longer-a-page-table.patch
kvm-mmu-free-pages-on-kvm-destruction.patch
kvm-mmu-replace-atomic-allocations-by-preallocated-objects.patch
kvm-mmu-detect-oom-conditions-and-propagate-error-to-userspace.patch
kvm-mmu-flush-guest-tlb-when-reducing-permissions-on-a-pte.patch
kvm-mmu-destroy-mmu-while-we-still-have-a-vcpu-left.patch
kvm-mmu-add-audit-code-to-check-mappings-etc-are-correct.patch
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