From f84fcb66568c0b00626f7f03e28db7d0dcba8098 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 1 Nov 2022 15:53:50 +0100 Subject: [PATCH] KVM: x86: hyper-v: Expose support for extended gva ranges for flush hypercalls Extended GVA ranges support bit seems to indicate whether lower 12 bits of GVA can be used to specify up to 4095 additional consequent GVAs to flush. This is somewhat described in TLFS. Previously, KVM was handling HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} requests by flushing the whole VPID so technically, extended GVA ranges were already supported. As such requests are handled more gently now, advertizing support for extended ranges starts making sense to reduce the size of TLB flush requests. Reviewed-by: Maxim Levitsky Reviewed-by: Sean Christopherson Signed-off-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Message-Id: <20221101145426.251680-13-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/hyperv-tlfs.h | 2 ++ arch/x86/kvm/hyperv.c | 1 + 2 files changed, 3 insertions(+) diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h index c5e0e5a06c0dc..6639979302ab7 100644 --- a/arch/x86/include/asm/hyperv-tlfs.h +++ b/arch/x86/include/asm/hyperv-tlfs.h @@ -61,6 +61,8 @@ #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE BIT(10) /* Support for debug MSRs available */ #define HV_FEATURE_DEBUG_MSRS_AVAILABLE BIT(11) +/* Support for extended gva ranges for flush hypercalls available */ +#define HV_FEATURE_EXT_GVA_RANGES_FLUSH BIT(14) /* * Support for returning hypercall output block via XMM * registers is available diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 6868c478617c0..fca9c51891f5f 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -2641,6 +2641,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, ent->ebx |= HV_DEBUGGING; ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE; ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE; + ent->edx |= HV_FEATURE_EXT_GVA_RANGES_FLUSH; /* * Direct Synthetic timers only make sense with in-kernel -- 2.30.2