KVM: x86: #PF error-code on R/W operations is wrong

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When emulating an instruction that reads the destination memory operand (i.e.,
instructions without the Mov flag in the emulator), the operand is first read.
If a page-fault is detected in this phase, the error-code which would be
delivered to the VM does not indicate that the access that caused the exception
is a write one. This does not conform with real hardware, and may cause the VM
to enter the page-fault handler twice for no reason (once for read, once for
write).

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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Nadav Amit 2014-12-25 02:52:16 +02:00 • committed by Paolo Bonzini

parent 7e71a59b25

commit c205fb7d7d

3 changed files with 17 additions and 13 deletions

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12

arch/x86/include/asm/kvm_host.h

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6

arch/x86/kvm/emulate.c

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12

arch/x86/kvm/mmu.h

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