Messages in this thread | | | Date | Tue, 30 May 2017 11:05:48 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH v2] KVM: x86: Avoid guest page table walk when gpa_available is set |
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On Fri, May 19, 2017 at 11:12:29AM -0400, Brijesh Singh wrote: > From: Brijesh Singh <brijesh.singh@amd.com> > > On AMD hardware when a guest causes a NPF 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> > --- > v1: http://marc.info/?l=kvm&m=149304930814202&w=2 > > Changes in v2: > - move gpa_val setting in pf_interception > > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/kvm/svm.c | 4 ++++ > arch/x86/kvm/x86.c | 14 +++++++------- > 3 files changed, 12 insertions(+), 7 deletions(-)
I havn't checked in detail, but maybe you have: Does that take nesting into account, where we might run on a shadow nested page-table and we actually get a nested gpa (which still needs translation) instead of a normal gpa?
Joerg
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