From b63cf42fd1d8c18fab71222321aaf356f63089c9 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 7 May 2014 16:29:48 +0300 Subject: [PATCH] kvm/x86: implement hv EOI assist It seems that it's easy to implement the EOI assist on top of the PV EOI feature: simply convert the page address to the format expected by PV EOI. Notes: -"No EOI required" is set only if interrupt injected is edge triggered; this is true because level interrupts are going through IOAPIC which disables PV EOI. In any case, if guest triggers EOI the bit will get cleared on exit. -For migration, set of HV_X64_MSR_APIC_ASSIST_PAGE sets KVM_PV_EOI_EN internally, so restoring HV_X64_MSR_APIC_ASSIST_PAGE seems sufficient In any case, bit is cleared on exit so worst case it's never re-enabled -no handling of PV EOI data is performed at HV_X64_MSR_EOI write; HV_X64_MSR_EOI is a separate optimization - it's an X2APIC replacement that lets you do EOI with an MSR and not IO. Signed-off-by: Michael S. Tsirkin Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index de0931cb3f58..41f673facf2f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1917,6 +1917,8 @@ static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 data) if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) { vcpu->arch.hv_vapic = data; + if (kvm_lapic_enable_pv_eoi(vcpu, 0)) + return 1; break; } gfn = data >> HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT; @@ -1927,6 +1929,8 @@ static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 data) return 1; vcpu->arch.hv_vapic = data; mark_page_dirty(vcpu->kvm, gfn); + if (kvm_lapic_enable_pv_eoi(vcpu, gfn_to_gpa(gfn) | KVM_MSR_ENABLED)) + return 1; break; } case HV_X64_MSR_EOI: -- 2.20.1