| Message ID | 20190823010709.24879-2-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Remove emulation_result enums | expand |
Sean Christopherson <sean.j.christopherson@intel.com> writes: > Move the stat.mmio_exits update into x86_emulate_instruction(). This is > both a bug fix, e.g. the current update flows will incorrectly increment > mmio_exits on emulation failure, and a preparatory change to set the > stage for eliminating EMULATE_DONE and company. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> This, however, makes me wonder why this is handled in x86-specific code in the first place, can we just count KVM_EXIT_MMIO exits when handling KVM_RUN? > --- > arch/x86/kvm/mmu.c | 2 -- > arch/x86/kvm/vmx/vmx.c | 1 - > arch/x86/kvm/x86.c | 2 ++ > 3 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 4c45ff0cfbd0..845e39d8a970 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -5437,8 +5437,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code, > case EMULATE_DONE: > return 1; > case EMULATE_USER_EXIT: > - ++vcpu->stat.mmio_exits; > - /* fall through */ > case EMULATE_FAIL: > return 0; > default: > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 570a233e272b..18286e5b5983 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -5200,7 +5200,6 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) > err = kvm_emulate_instruction(vcpu, 0); > > if (err == EMULATE_USER_EXIT) { > - ++vcpu->stat.mmio_exits; > ret = 0; > goto out; > } > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index b4cfd786d0b6..cd425f54096a 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6598,6 +6598,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, > } > r = EMULATE_USER_EXIT; > } else if (vcpu->mmio_needed) { > + ++vcpu->stat.mmio_exits; > + > if (!vcpu->mmio_is_write) > writeback = false; > r = EMULATE_USER_EXIT;
On Fri, Aug 23, 2019 at 11:15:18AM +0200, Vitaly Kuznetsov wrote: > Sean Christopherson <sean.j.christopherson@intel.com> writes: > > > Move the stat.mmio_exits update into x86_emulate_instruction(). This is > > both a bug fix, e.g. the current update flows will incorrectly increment > > mmio_exits on emulation failure, and a preparatory change to set the > > stage for eliminating EMULATE_DONE and company. > > > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > > Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> > > This, however, makes me wonder why this is handled in x86-specific code > in the first place, can we just count KVM_EXIT_MMIO exits when handling > KVM_RUN? struct kvm_vcpu_stat is arch specific. At a glance, everyone is counting similar things, but often in slightly different ways. E.g. PowerPC and ARM count MMIO exits, but PowerPC counts all exits, ARM has separate counters for in-kernel vs. userspace, and x86 counts only userspace.
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 4c45ff0cfbd0..845e39d8a970 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -5437,8 +5437,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code, case EMULATE_DONE: return 1; case EMULATE_USER_EXIT: - ++vcpu->stat.mmio_exits; - /* fall through */ case EMULATE_FAIL: return 0; default: diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 570a233e272b..18286e5b5983 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5200,7 +5200,6 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) err = kvm_emulate_instruction(vcpu, 0); if (err == EMULATE_USER_EXIT) { - ++vcpu->stat.mmio_exits; ret = 0; goto out; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b4cfd786d0b6..cd425f54096a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6598,6 +6598,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, } r = EMULATE_USER_EXIT; } else if (vcpu->mmio_needed) { + ++vcpu->stat.mmio_exits; + if (!vcpu->mmio_is_write) writeback = false; r = EMULATE_USER_EXIT;
Move the stat.mmio_exits update into x86_emulate_instruction(). This is both a bug fix, e.g. the current update flows will incorrectly increment mmio_exits on emulation failure, and a preparatory change to set the stage for eliminating EMULATE_DONE and company. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/mmu.c | 2 -- arch/x86/kvm/vmx/vmx.c | 1 - arch/x86/kvm/x86.c | 2 ++ 3 files changed, 2 insertions(+), 3 deletions(-)