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From: "Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>,
	"rkrcmar@redhat.com" <rkrcmar@redhat.com>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"graf@amazon.com" <graf@amazon.com>,
	"jschoenh@amazon.de" <jschoenh@amazon.de>,
	"karahmed@amazon.de" <karahmed@amazon.de>,
	"rimasluk@amazon.com" <rimasluk@amazon.com>,
	"Grimm, Jon" <Jon.Grimm@amd.com>,
	"Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>
Subject: [PATCH v2 14/15] kvm: ioapic: Delay update IOAPIC EOI for RTC
Date: Thu, 15 Aug 2019 16:25:20 +0000
Message-ID: <1565886293-115836-15-git-send-email-suravee.suthikulpanit@amd.com> (raw)
In-Reply-To: <1565886293-115836-1-git-send-email-suravee.suthikulpanit@amd.com>

In-kernel IOAPIC does not update RTC pending EOI info with AMD SVM /w AVIC
when interrupt is delivered as edge-triggered since AMD processors
cannot exit on EOI for these interrupts.

Add code to also check LAPIC pending EOI before injecting any new RTC
interrupts on AMD SVM when AVIC is activated.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 arch/x86/kvm/ioapic.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index 1add1bc..45e7bb0 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -39,6 +39,7 @@
 #include <asm/processor.h>
 #include <asm/page.h>
 #include <asm/current.h>
+#include <asm/virtext.h>
 #include <trace/events/kvm.h>
 
 #include "ioapic.h"
@@ -173,6 +174,7 @@ static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
 	return false;
 }
 
+#define APIC_DEST_NOSHORT		0x0
 static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
 		int irq_level, bool line_status)
 {
@@ -201,10 +203,36 @@ static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
 	 * interrupts lead to time drift in Windows guests.  So we track
 	 * EOI manually for the RTC interrupt.
 	 */
-	if (irq == RTC_GSI && line_status &&
-		rtc_irq_check_coalesced(ioapic)) {
-		ret = 0;
-		goto out;
+	if (irq == RTC_GSI && line_status) {
+		struct kvm *kvm = ioapic->kvm;
+		union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
+
+		/*
+		 * Since, AMD SVM AVIC accelerates write access to APIC EOI
+		 * register for edge-trigger interrupts, IOAPIC will not be
+		 * able to receive the EOI. In this case, we do lazy update
+		 * of the pending EOI when trying to set IOAPIC irq for RTC.
+		 */
+		if (cpu_has_svm(NULL) &&
+		    (kvm->arch.apicv_state == APICV_ACTIVATED) &&
+		    (entry->fields.trig_mode == IOAPIC_EDGE_TRIG)) {
+			int i;
+			struct kvm_vcpu *vcpu;
+
+			kvm_for_each_vcpu(i, vcpu, kvm)
+				if (kvm_apic_match_dest(vcpu, NULL,
+							KVM_APIC_DEST_NOSHORT,
+							entry->fields.dest_id,
+							entry->fields.dest_mode)) {
+					__rtc_irq_eoi_tracking_restore_one(vcpu);
+					break;
+				}
+		}
+
+		if (rtc_irq_check_coalesced(ioapic)) {
+			ret = 0;
+			goto out;
+		}
 	}
 
 	old_irr = ioapic->irr;
-- 
1.8.3.1


  parent reply index

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-15 16:25 [PATCH v2 00/15] kvm: x86: Support AMD SVM AVIC w/ in-kernel irqchip mode Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 01/15] kvm: x86: Modify kvm_x86_ops.get_enable_apicv() to use struct kvm parameter Suthikulpanit, Suravee
2019-08-27  7:15   ` Vitaly Kuznetsov
2019-08-15 16:25 ` [PATCH v2 02/15] kvm: x86: Introduce KVM APICv state Suthikulpanit, Suravee
2019-08-19  9:49   ` Alexander Graf
2019-08-26 19:06     ` Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 03/15] kvm: Add arch-specific per-VM debugfs support Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 04/15] kvm: x86: Add per-VM APICv state debugfs Suthikulpanit, Suravee
2019-08-19  9:57   ` Alexander Graf
2019-08-26 19:41     ` Suthikulpanit, Suravee
2019-08-27  8:20       ` Alexander Graf
2019-08-28 18:39         ` Suthikulpanit, Suravee
2019-08-28 19:36           ` Graf (AWS), Alexander
2019-08-15 16:25 ` [PATCH v2 05/15] kvm: lapic: Introduce APICv update helper function Suthikulpanit, Suravee
2019-08-27  7:22   ` Vitaly Kuznetsov
2019-08-15 16:25 ` [PATCH v2 06/15] kvm: x86: Add support for activate/de-activate APICv at runtime Suthikulpanit, Suravee
2019-08-27  7:29   ` Vitaly Kuznetsov
2019-08-27  8:05     ` Alexander Graf
2019-08-15 16:25 ` [PATCH v2 07/15] kvm: x86: svm: Add support to activate/deactivate posted interrupts Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 08/15] svm: Add support for setup/destroy virutal APIC backing page for AVIC Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 09/15] svm: Add support for activate/deactivate AVIC at runtime Suthikulpanit, Suravee
2019-08-19 10:28   ` Alexander Graf
2019-08-15 16:25 ` [PATCH v2 10/15] kvm: x86: hyperv: Use APICv deactivate request interface Suthikulpanit, Suravee
2019-08-19 10:31   ` Alexander Graf
2019-08-15 16:25 ` [PATCH v2 11/15] svm: Temporary deactivate AVIC during ExtINT handling Suthikulpanit, Suravee
2019-08-19 10:35   ` Alexander Graf
2019-08-28 15:17     ` Suthikulpanit, Suravee
2019-08-28 19:37       ` Graf (AWS), Alexander
2019-09-10 15:46         ` Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 12/15] kvm: i8254: Check LAPIC EOI pending when injecting irq on SVM AVIC Suthikulpanit, Suravee
2019-08-19 10:42   ` Alexander Graf
2019-08-26 20:46     ` Suthikulpanit, Suravee
2019-08-27  9:10       ` Alexander Graf
2019-09-13 14:50         ` Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 13/15] kvm: lapic: Clean up APIC predefined macros Suthikulpanit, Suravee
2019-08-15 16:25 ` Suthikulpanit, Suravee [this message]
2019-08-19 11:00   ` [PATCH v2 14/15] kvm: ioapic: Delay update IOAPIC EOI for RTC Alexander Graf
2019-09-04  2:06     ` Suthikulpanit, Suravee
2019-08-15 16:25 ` [PATCH v2 15/15] svm: Allow AVIC with in-kernel irqchip mode Suthikulpanit, Suravee

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