On 09/06/21 17:09, Vitaly Kuznetsov wrote:
Changes since v2: - First two patches got merged, rebase. - Use 'enable_apicv = avic = ...' in PATCH1 [Paolo] - Collect R-b tags for PATCH2 [Sean, Max] - Use hv_apicv_update_work() to get out of SRCU lock [Max] - "KVM: x86: Check for pending interrupts when APICv is getting disabled" added. Original description: APICV_INHIBIT_REASON_HYPERV is currently unconditionally forced upon SynIC activation as SynIC's AutoEOI is incompatible with APICv/AVIC. It is, however, possible to track whether the feature was actually used by the guest and only inhibit APICv/AVIC when needed. The series can be tested with the followin hack: diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 9a48f138832d..65a9974f80d9 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -147,6 +147,13 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) vcpu->arch.ia32_misc_enable_msr & MSR_IA32_MISC_ENABLE_MWAIT); } + + /* Dirty hack: force HV_DEPRECATING_AEOI_RECOMMENDED. Not to be merged! */ + best = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO, 0); + if (best) { + best->eax &= ~HV_X64_APIC_ACCESS_RECOMMENDED; + best->eax |= HV_DEPRECATING_AEOI_RECOMMENDED; + } } EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime);Vitaly Kuznetsov (4):KVM: x86: Use common 'enable_apicv' variable for both APICv and AVIC KVM: x86: Drop vendor specific functions for APICv/AVIC enablement KVM: x86: Check for pending interrupts when APICv is getting disabled KVM: x86: hyper-v: Deactivate APICv only when AutoEOI feature is in use arch/x86/include/asm/kvm_host.h | 9 +++++- arch/x86/kvm/hyperv.c | 51 +++++++++++++++++++++++++++++---- arch/x86/kvm/svm/avic.c | 14 ++++----- arch/x86/kvm/svm/svm.c | 22 ++++++++------ arch/x86/kvm/svm/svm.h | 2 -- arch/x86/kvm/vmx/capabilities.h | 1 - arch/x86/kvm/vmx/vmx.c | 2 -- arch/x86/kvm/x86.c | 18 ++++++++++-- 8 files changed, 86 insertions(+), 33 deletions(-)
Queued, thanks. Paolo
