Re: [PATCH v2] KVM: x86: check ISR and TMR to construct eoi exit bitmap

[Wanpeng Li <wanpeng.li@linux.intel.com>]

Hi Wei,
On Thu, Aug 14, 2014 at 03:16:25AM +0800, Wei Wang wrote:
>From: Yang Zhang <yang.z.zhang@Intel.com>
>
>Guest may mask the IOAPIC entry before issue EOI. In such case,
>EOI will not be intercepted by hypervisor due to the corrensponding
>bit in eoi exit bitmap is not setting.
>
>The solution is to check ISR + TMR to construct the EOI exit bitmap.
>
>This patch is a better fixing for the issue that commit "0f6c0a740b"
>tries to solve.
>

I think you miss the changlog.

Regards,
Wanpeng Li 

>Tested-by: Alex Williamson <alex.williamson@redhat.com>
>Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
>Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>---
> arch/x86/kvm/lapic.c |   17 +++++++++++++++++
> arch/x86/kvm/lapic.h |    2 ++
> arch/x86/kvm/x86.c   |    9 +++++++++
> virt/kvm/ioapic.c    |    7 ++++---
> 4 files changed, 32 insertions(+), 3 deletions(-)
>
>diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
>index 08e8a89..0ed4bcb 100644
>--- a/arch/x86/kvm/lapic.c
>+++ b/arch/x86/kvm/lapic.c
>@@ -515,6 +515,23 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu)
> 	__clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention);
> }
> 
>+void kvm_apic_zap_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
>+		u32 *tmr)
>+{
>+	u32 i, reg_off, intr_in_service;
>+	struct kvm_lapic *apic = vcpu->arch.apic;
>+
>+	for (i = 0; i < 8; i++) {
>+		reg_off = 0x10 * i;
>+		intr_in_service = apic_read_reg(apic, APIC_ISR + reg_off) &
>+			kvm_apic_get_reg(apic, APIC_TMR + reg_off);
>+		if (intr_in_service) {
>+			*((u32 *)eoi_exit_bitmap + i) |= intr_in_service;
>+			tmr[i] |= intr_in_service;
>+		}
>+	}
>+}
>+
> void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
> {
> 	struct kvm_lapic *apic = vcpu->arch.apic;
>diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
>index 6a11845..4ee3d70 100644
>--- a/arch/x86/kvm/lapic.h
>+++ b/arch/x86/kvm/lapic.h
>@@ -53,6 +53,8 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value);
> u64 kvm_lapic_get_base(struct kvm_vcpu *vcpu);
> void kvm_apic_set_version(struct kvm_vcpu *vcpu);
> 
>+void kvm_apic_zap_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
>+		u32 *tmr);
> void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);
> void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
> int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);
>diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>index 204422d..755b556 100644
>--- a/arch/x86/kvm/x86.c
>+++ b/arch/x86/kvm/x86.c
>@@ -6005,6 +6005,15 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
> 	memset(tmr, 0, 32);
> 
> 	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
>+	/*
>+	 * Guest may mask the IOAPIC entry before issue EOI. In such case,
>+	 * EOI will not be intercepted by hypervisor due to the corrensponding
>+	 * bit in eoi exit bitmap is not setting.
>+	 *
>+	 * The solution is to check ISR + TMR to construct the EOI exit bitmap.
>+	 */
>+	kvm_apic_zap_eoi_exitmap(vcpu, eoi_exit_bitmap, tmr);
>+
> 	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
> 	kvm_apic_update_tmr(vcpu, tmr);
> }
>diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
>index e8ce34c..2458a1d 100644
>--- a/virt/kvm/ioapic.c
>+++ b/virt/kvm/ioapic.c
>@@ -254,9 +254,10 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
> 	spin_lock(&ioapic->lock);
> 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
> 		e = &ioapic->redirtbl[index];
>-		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
>-		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
>-		    index == RTC_GSI) {
>+		if (!e->fields.mask &&
>+			(e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
>+			 kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
>+				 index) || index == RTC_GSI)) {
> 			if (kvm_apic_match_dest(vcpu, NULL, 0,
> 				e->fields.dest_id, e->fields.dest_mode)) {
> 				__set_bit(e->fields.vector,
>-- 
>1.7.1
>
>--
>To unsubscribe from this list: send the line "unsubscribe kvm" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html