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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>,
	"vkuznets@redhat.com" <vkuznets@redhat.com>,
	"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 v3 04/16] kvm: x86: Add support for activate/de-activate APICv at runtime
Date: Fri, 13 Sep 2019 19:00:53 +0000	[thread overview]
Message-ID: <1568401242-260374-5-git-send-email-suravee.suthikulpanit@amd.com> (raw)
In-Reply-To: <1568401242-260374-1-git-send-email-suravee.suthikulpanit@amd.com>

Certain runtime conditions require APICv to be temporary deactivated.
However, current implementation only support permanently deactivate
APICv at runtime (mainly used when running Hyper-V guest).

In addition, for AMD, when activate / deactivate APICv during runtime,
all vcpus in the VM has to be operating in the same APICv mode, which
requires the requesting (main) vcpu to notify others.

So, introduce interfaces to request all vcpus to activate/deactivate
APICv.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 arch/x86/include/asm/kvm_host.h |  9 ++++
 arch/x86/kvm/x86.c              | 95 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 562bfbd..a50fca1b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -78,6 +78,10 @@
 #define KVM_REQ_HV_STIMER		KVM_ARCH_REQ(22)
 #define KVM_REQ_LOAD_EOI_EXITMAP	KVM_ARCH_REQ(23)
 #define KVM_REQ_GET_VMCS12_PAGES	KVM_ARCH_REQ(24)
+#define KVM_REQ_APICV_ACTIVATE		\
+	KVM_ARCH_REQ_FLAGS(25, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
+#define KVM_REQ_APICV_DEACTIVATE	\
+	KVM_ARCH_REQ_FLAGS(26, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 
 #define CR0_RESERVED_BITS                                               \
 	(~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \
@@ -1098,6 +1102,8 @@ struct kvm_x86_ops {
 	void (*enable_irq_window)(struct kvm_vcpu *vcpu);
 	void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr);
 	bool (*get_enable_apicv)(struct kvm *kvm);
+	void (*pre_update_apicv_exec_ctrl)(struct kvm_vcpu *vcpu,
+					   bool activate);
 	void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu);
 	void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);
 	void (*hwapic_isr_update)(struct kvm_vcpu *vcpu, int isr);
@@ -1425,6 +1431,9 @@ gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
 				struct x86_exception *exception);
 
 void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu);
+void kvm_vcpu_activate_apicv(struct kvm_vcpu *vcpu);
+void kvm_make_apicv_activate_request(struct kvm_vcpu *vcpu);
+void kvm_make_apicv_deactivate_request(struct kvm_vcpu *vcpu, bool disable);
 
 int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 64d275e..446df2b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -26,6 +26,7 @@
 #include "cpuid.h"
 #include "pmu.h"
 #include "hyperv.h"
+#include "lapic.h"
 
 #include <linux/clocksource.h>
 #include <linux/interrupt.h>
@@ -7184,6 +7185,22 @@ static void kvm_pv_kick_cpu_op(struct kvm *kvm, unsigned long flags, int apicid)
 	kvm_irq_delivery_to_apic(kvm, NULL, &lapic_irq, NULL);
 }
 
+void kvm_vcpu_activate_apicv(struct kvm_vcpu *vcpu)
+{
+	if (!lapic_in_kernel(vcpu)) {
+		WARN_ON_ONCE(!vcpu->arch.apicv_active);
+		return;
+	}
+	if (vcpu->arch.apicv_active)
+		return;
+
+	vcpu->arch.apicv_active = true;
+	kvm_apic_update_apicv(vcpu);
+
+	kvm_x86_ops->refresh_apicv_exec_ctrl(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_vcpu_activate_apicv);
+
 void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu)
 {
 	if (!lapic_in_kernel(vcpu)) {
@@ -7194,8 +7211,10 @@ void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu)
 		return;
 
 	vcpu->arch.apicv_active = false;
+	kvm_apic_update_apicv(vcpu);
 	kvm_x86_ops->refresh_apicv_exec_ctrl(vcpu);
 }
+EXPORT_SYMBOL_GPL(kvm_vcpu_deactivate_apicv);
 
 static void kvm_sched_yield(struct kvm *kvm, unsigned long dest_id)
 {
@@ -7711,6 +7730,78 @@ void kvm_make_scan_ioapic_request(struct kvm *kvm)
 	kvm_make_all_cpus_request(kvm, KVM_REQ_SCAN_IOAPIC);
 }
 
+/*
+ * NOTE:
+ * With kvm_make_apicv_[activate|deactivate]_request(), we could run into
+ * a situation where a vcpu tries to send a new request to a target vcpu before
+ * it can handle the prior request.
+ *
+ * For example:
+ *
+ *     vcpu0                                vcpu1
+ *
+ *     kvm_make_apicv_activate_request()    ...
+ *     Handle KVM_REQ_APICV_ACTIVATE        KVM_REQ_APICV_ACTIVATE==1
+ *     vcpu_run()                           ...
+ *     ...
+ *     ...
+ *     kvm_make_apicv_deactivate_request()  ...
+ *
+ * Here, vcpu0 would have to clear stale apicv activate/deactivate
+ * request before handling new one.
+ */
+void kvm_make_apicv_activate_request(struct kvm_vcpu *vcpu)
+{
+	int i;
+	struct kvm_vcpu *v;
+	struct kvm *kvm = vcpu->kvm;
+
+	mutex_lock(&kvm->arch.apicv_lock);
+	if (kvm->arch.apicv_state != APICV_SUSPENDED) {
+		mutex_unlock(&kvm->arch.apicv_lock);
+		return;
+	}
+
+	kvm_for_each_vcpu(i, v, kvm)
+		kvm_clear_request(KVM_REQ_APICV_DEACTIVATE, v);
+
+	if (kvm_x86_ops->pre_update_apicv_exec_ctrl)
+		kvm_x86_ops->pre_update_apicv_exec_ctrl(vcpu, true);
+
+	kvm->arch.apicv_state = APICV_ACTIVATED;
+
+	kvm_make_all_cpus_request(kvm, KVM_REQ_APICV_ACTIVATE);
+
+	mutex_unlock(&kvm->arch.apicv_lock);
+}
+EXPORT_SYMBOL_GPL(kvm_make_apicv_activate_request);
+
+void kvm_make_apicv_deactivate_request(struct kvm_vcpu *vcpu, bool disable)
+{
+	int i;
+	struct kvm_vcpu *v;
+	struct kvm *kvm = vcpu->kvm;
+
+	mutex_lock(&kvm->arch.apicv_lock);
+	if (kvm->arch.apicv_state != APICV_ACTIVATED) {
+		mutex_unlock(&kvm->arch.apicv_lock);
+		return;
+	}
+
+	kvm_for_each_vcpu(i, v, kvm)
+		kvm_clear_request(KVM_REQ_APICV_ACTIVATE, v);
+
+	if (kvm_x86_ops->pre_update_apicv_exec_ctrl)
+		kvm_x86_ops->pre_update_apicv_exec_ctrl(vcpu, false);
+
+	kvm->arch.apicv_state = disable ? APICV_DISABLED : APICV_SUSPENDED;
+
+	kvm_make_all_cpus_request(kvm, KVM_REQ_APICV_DEACTIVATE);
+
+	mutex_unlock(&kvm->arch.apicv_lock);
+}
+EXPORT_SYMBOL_GPL(kvm_make_apicv_deactivate_request);
+
 static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
 {
 	if (!kvm_apic_present(vcpu))
@@ -7897,6 +7988,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		 */
 		if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu))
 			kvm_hv_process_stimers(vcpu);
+		if (kvm_check_request(KVM_REQ_APICV_ACTIVATE, vcpu))
+			kvm_vcpu_activate_apicv(vcpu);
+		if (kvm_check_request(KVM_REQ_APICV_DEACTIVATE, vcpu))
+			kvm_vcpu_deactivate_apicv(vcpu);
 	}
 
 	if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
-- 
1.8.3.1


  parent reply	other threads:[~2019-09-13 19:01 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-13 19:00 [PATCH v3 00/16] kvm: x86: Support AMD SVM AVIC w/ in-kernel irqchip mode Suthikulpanit, Suravee
2019-09-13 19:00 ` [PATCH v3 01/16] kvm: x86: Modify kvm_x86_ops.get_enable_apicv() to use struct kvm parameter Suthikulpanit, Suravee
2019-09-13 19:00 ` [PATCH v3 02/16] kvm: x86: Introduce KVM APICv state Suthikulpanit, Suravee
2019-09-13 19:00 ` [PATCH v3 03/16] kvm: lapic: Introduce APICv update helper function Suthikulpanit, Suravee
2019-09-13 19:00 ` Suthikulpanit, Suravee [this message]
2019-10-09  8:38   ` [PATCH v3 04/16] kvm: x86: Add support for activate/de-activate APICv at runtime Paolo Bonzini
2019-09-13 19:00 ` [PATCH v3 05/16] kvm: x86: Add APICv activate/deactivate request trace points Suthikulpanit, Suravee
2019-09-13 19:00 ` [PATCH v3 06/16] kvm: x86: svm: Add support to activate/deactivate posted interrupts Suthikulpanit, Suravee
2019-10-09  8:25   ` Paolo Bonzini
2019-09-13 19:00 ` [PATCH v3 07/16] svm: Add support for setup/destroy virutal APIC backing page for AVIC Suthikulpanit, Suravee
2019-09-13 19:00 ` [PATCH v3 08/16] svm: Add support for activate/deactivate AVIC at runtime Suthikulpanit, Suravee
2019-09-13 19:01 ` [PATCH v3 09/16] kvm: x86: hyperv: Use APICv deactivate request interface Suthikulpanit, Suravee
2019-10-09  9:21   ` Paolo Bonzini
2019-09-13 19:01 ` [PATCH v3 10/16] svm: Disable AVIC when launching guest with SVM support Suthikulpanit, Suravee
2019-09-13 19:01 ` [PATCH v3 11/16] svm: Temporary deactivate AVIC during ExtINT handling Suthikulpanit, Suravee
2019-09-13 19:01 ` [PATCH v3 12/16] kvm: x86: Introduce struct kvm_x86_ops.apicv_eoi_accelerate Suthikulpanit, Suravee
2019-09-13 19:01 ` [PATCH v3 13/16] kvm: lapic: Clean up APIC predefined macros Suthikulpanit, Suravee
2019-09-13 19:01 ` [PATCH v3 14/16] kvm: ioapic: Refactor kvm_ioapic_update_eoi() Suthikulpanit, Suravee
2019-09-13 19:01 ` [PATCH v3 15/16] kvm: x86: ioapic: Lazy update IOAPIC EOI Suthikulpanit, Suravee
2019-10-09  9:21   ` Paolo Bonzini
2019-10-09  9:55     ` Roman Kagan
2019-10-31 15:17     ` Suthikulpanit, Suravee
2019-10-31 23:09       ` Paolo Bonzini
2019-09-13 19:01 ` [PATCH v3 16/16] svm: Allow AVIC with in-kernel irqchip mode Suthikulpanit, Suravee
2019-10-08 18:44 ` [PATCH v3 00/16] kvm: x86: Support AMD SVM AVIC w/ " Suthikulpanit, Suravee
2019-10-09  9:01   ` Paolo Bonzini

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