KVM: x86: Avoid guest page table walk when gpa_available is set

Browse source

When a guest causes a page fault which requires emulation, the
vcpu->arch.gpa_available flag is set to indicate that cr2 contains a
valid GPA.

Currently, emulator_read_write_onepage() makes use of gpa_available flag
to avoid a guest page walk for a known MMIO regions. Lets not limit
the gpa_available optimization to just MMIO region. The patch extends
the check to avoid page walk whenever gpa_available flag is set.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
[Fix EPT=0 according to Wanpeng Li's fix, plus ensure VMX also uses the
 new code. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[Moved "ret < 0" to the else brach, as per David's review. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

...

This commit is contained in:

Brijesh Singh 2017-08-17 18:36:57 +02:00 • committed by Radim Krčmář

parent e08d26f071

commit 618232e219

5 changed files with 17 additions and 22 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

3

arch/x86/include/asm/kvm_host.h

View file

6

arch/x86/kvm/mmu.c

View file

2

arch/x86/kvm/svm.c

View file

4

arch/x86/kvm/vmx.c

View file

24

arch/x86/kvm/x86.c

View file