KVM Archive on lore.kernel.org
 help / color / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
	vkuznets@redhat.com
Subject: [PATCH 06/43] KVM: VMX: Handle NMIs, #MCs and async #PFs in common irqs-disabled fn
Date: Thu, 13 Jun 2019 19:02:52 +0200
Message-ID: <1560445409-17363-7-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1560445409-17363-1-git-send-email-pbonzini@redhat.com>

From: Sean Christopherson <sean.j.christopherson@intel.com>

Per commit 1b6269db3f833 ("KVM: VMX: Handle NMIs before enabling
interrupts and preemption"), NMIs are handled directly in vmx_vcpu_run()
to "make sure we handle NMI on the current cpu, and that we don't
service maskable interrupts before non-maskable ones".  The other
exceptions handled by complete_atomic_exit(), e.g. async #PF and #MC,
have similar requirements, and are located there to avoid extra VMREADs
since VMX bins hardware exceptions and NMIs into a single exit reason.

Clean up the code and eliminate the vaguely named complete_atomic_exit()
by moving the interrupts-disabled exception and NMI handling into the
existing handle_external_intrs() callback, and rename the callback to
a more appropriate name.  Rename VMexit handlers throughout so that the
atomic and non-atomic counterparts have similar names.

In addition to improving code readability, this also ensures the NMI
handler is run with the host's debug registers loaded in the unlikely
event that the user is debugging NMIs.  Accuracy of the last_guest_tsc
field is also improved when handling NMIs (and #MCs) as the handler
will run after updating said field.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Naming cleanups. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/asm/kvm_host.h |  2 +-
 arch/x86/kvm/svm.c              |  4 ++--
 arch/x86/kvm/vmx/vmx.c          | 33 ++++++++++++++++++---------------
 arch/x86/kvm/x86.c              |  2 +-
 4 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 35e7937cc9ac..f46a12a5cf2e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1117,7 +1117,7 @@ struct kvm_x86_ops {
 	int (*check_intercept)(struct kvm_vcpu *vcpu,
 			       struct x86_instruction_info *info,
 			       enum x86_intercept_stage stage);
-	void (*handle_external_intr)(struct kvm_vcpu *vcpu);
+	void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu);
 	bool (*mpx_supported)(void);
 	bool (*xsaves_supported)(void);
 	bool (*umip_emulated)(void);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index acc09e9fc173..bbc31f7213ed 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6172,7 +6172,7 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
-static void svm_handle_external_intr(struct kvm_vcpu *vcpu)
+static void svm_handle_exit_irqoff(struct kvm_vcpu *vcpu)
 {
 	kvm_before_interrupt(vcpu);
 	local_irq_enable();
@@ -7268,7 +7268,7 @@ static bool svm_need_emulation_on_page_fault(struct kvm_vcpu *vcpu)
 	.set_tdp_cr3 = set_tdp_cr3,
 
 	.check_intercept = svm_check_intercept,
-	.handle_external_intr = svm_handle_external_intr,
+	.handle_exit_irqoff = svm_handle_exit_irqoff,
 
 	.request_immediate_exit = __kvm_request_immediate_exit,
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 963c8c409223..2b182f58c126 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4437,11 +4437,11 @@ static void kvm_machine_check(void)
 
 static int handle_machine_check(struct kvm_vcpu *vcpu)
 {
-	/* already handled by vcpu_run */
+	/* handled by vmx_vcpu_run() */
 	return 1;
 }
 
-static int handle_exception(struct kvm_vcpu *vcpu)
+static int handle_exception_nmi(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	struct kvm_run *kvm_run = vcpu->run;
@@ -4454,7 +4454,7 @@ static int handle_exception(struct kvm_vcpu *vcpu)
 	intr_info = vmx->exit_intr_info;
 
 	if (is_machine_check(intr_info) || is_nmi(intr_info))
-		return 1;  /* already handled by vmx_complete_atomic_exit */
+		return 1; /* handled by handle_exception_nmi_irqoff() */
 
 	if (is_invalid_opcode(intr_info))
 		return handle_ud(vcpu);
@@ -5462,7 +5462,7 @@ static int handle_encls(struct kvm_vcpu *vcpu)
  * to be done to userspace and return 0.
  */
 static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
-	[EXIT_REASON_EXCEPTION_NMI]           = handle_exception,
+	[EXIT_REASON_EXCEPTION_NMI]           = handle_exception_nmi,
 	[EXIT_REASON_EXTERNAL_INTERRUPT]      = handle_external_interrupt,
 	[EXIT_REASON_TRIPLE_FAULT]            = handle_triple_fault,
 	[EXIT_REASON_NMI_WINDOW]	      = handle_nmi_window,
@@ -6100,11 +6100,8 @@ static void vmx_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 	memset(vmx->pi_desc.pir, 0, sizeof(vmx->pi_desc.pir));
 }
 
-static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
+static void handle_exception_nmi_irqoff(struct vcpu_vmx *vmx)
 {
-	if (vmx->exit_reason != EXIT_REASON_EXCEPTION_NMI)
-		return;
-
 	vmx->exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
 
 	/* if exit due to PF check for async PF */
@@ -6123,7 +6120,7 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
 	}
 }
 
-static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
+static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu)
 {
 	unsigned int vector;
 	unsigned long entry;
@@ -6133,9 +6130,6 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
 	gate_desc *desc;
 	u32 intr_info;
 
-	if (to_vmx(vcpu)->exit_reason != EXIT_REASON_EXTERNAL_INTERRUPT)
-		return;
-
 	intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
 	if (WARN_ONCE(!is_external_intr(intr_info),
 	    "KVM: unexpected VM-Exit interrupt info: 0x%x", intr_info))
@@ -6170,7 +6164,17 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu)
 
 	kvm_after_interrupt(vcpu);
 }
-STACK_FRAME_NON_STANDARD(vmx_handle_external_intr);
+STACK_FRAME_NON_STANDARD(handle_external_interrupt_irqoff);
+
+static void vmx_handle_exit_irqoff(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	if (vmx->exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT)
+		handle_external_interrupt_irqoff(vcpu);
+	else if (vmx->exit_reason == EXIT_REASON_EXCEPTION_NMI)
+		handle_exception_nmi_irqoff(vmx);
+}
 
 static bool vmx_has_emulated_msr(int index)
 {
@@ -6540,7 +6544,6 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	vmx->loaded_vmcs->launched = 1;
 	vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
 
-	vmx_complete_atomic_exit(vmx);
 	vmx_recover_nmi_blocking(vmx);
 	vmx_complete_interrupts(vmx);
 }
@@ -7694,7 +7697,7 @@ static __exit void hardware_unsetup(void)
 	.set_tdp_cr3 = vmx_set_cr3,
 
 	.check_intercept = vmx_check_intercept,
-	.handle_external_intr = vmx_handle_external_intr,
+	.handle_exit_irqoff = vmx_handle_exit_irqoff,
 	.mpx_supported = vmx_mpx_supported,
 	.xsaves_supported = vmx_xsaves_supported,
 	.umip_emulated = vmx_umip_emulated,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6e2f53cd8ea8..432f9f8c3d42 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7999,7 +7999,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 	vcpu->mode = OUTSIDE_GUEST_MODE;
 	smp_wmb();
 
-	kvm_x86_ops->handle_external_intr(vcpu);
+	kvm_x86_ops->handle_exit_irqoff(vcpu);
 
 	++vcpu->stat.exits;
 
-- 
1.8.3.1



  parent reply index

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-13 17:02 [PATCH 00/43] VMX optimizations Paolo Bonzini
2019-06-13 17:02 ` [PATCH 01/43] KVM: VMX: Fix handling of #MC that occurs during VM-Entry Paolo Bonzini
2019-06-13 17:24   ` Jim Mattson
2019-06-13 17:02 ` [PATCH 02/43] kvm: nVMX: small cleanup in handle_exception Paolo Bonzini
2019-06-13 17:02 ` [PATCH 03/43] KVM: VMX: Read cached VM-Exit reason to detect external interrupt Paolo Bonzini
2019-06-13 17:02 ` [PATCH 04/43] KVM: VMX: Store the host kernel's IDT base in a global variable Paolo Bonzini
2019-06-13 17:02 ` [PATCH 05/43] KVM: x86: Move kvm_{before,after}_interrupt() calls to vendor code Paolo Bonzini
2019-06-13 17:02 ` Paolo Bonzini [this message]
2019-06-13 17:02 ` [PATCH 07/43] KVM: nVMX: Intercept VMWRITEs to read-only shadow VMCS fields Paolo Bonzini
2019-06-13 17:02 ` [PATCH 08/43] KVM: nVMX: Intercept VMWRITEs to GUEST_{CS,SS}_AR_BYTES Paolo Bonzini
2019-06-13 17:02 ` [PATCH 09/43] KVM: nVMX: Track vmcs12 offsets for shadowed VMCS fields Paolo Bonzini
2019-06-13 17:02 ` [PATCH 10/43] KVM: nVMX: Lift sync_vmcs12() out of prepare_vmcs12() Paolo Bonzini
2019-06-13 17:02 ` [PATCH 11/43] KVM: nVMX: Use descriptive names for VMCS sync functions and flags Paolo Bonzini
2019-06-13 17:02 ` [PATCH 12/43] KVM: nVMX: Add helpers to identify shadowed VMCS fields Paolo Bonzini
2019-06-14 16:10   ` Sean Christopherson
2019-06-13 17:02 ` [PATCH 13/43] KVM: nVMX: Sync rarely accessed guest fields only when needed Paolo Bonzini
2019-06-13 17:03 ` [PATCH 14/43] KVM: nVMX: Rename prepare_vmcs02_*_full to prepare_vmcs02_*_rare Paolo Bonzini
2019-06-13 17:03 ` [PATCH 15/43] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value Paolo Bonzini
2019-06-13 17:03 ` [PATCH 16/43] KVM: nVMX: Always sync GUEST_BNDCFGS when it comes from vmcs01 Paolo Bonzini
     [not found]   ` <20190615221602.93C5721851@mail.kernel.org>
2019-06-15 22:40     ` Liran Alon
2019-06-13 17:03 ` [PATCH 17/43] KVM: nVMX: Write ENCLS-exiting bitmap once per vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 18/43] KVM: nVMX: Don't rewrite GUEST_PML_INDEX during nested VM-Entry Paolo Bonzini
2019-06-13 17:03 ` [PATCH 19/43] KVM: VMX: simplify vmx_prepare_switch_to_{guest,host} Paolo Bonzini
2019-06-13 17:03 ` [PATCH 20/43] KVM: nVMX: Don't "put" vCPU or host state when switching VMCS Paolo Bonzini
2019-06-13 17:03 ` [PATCH 21/43] KVM: nVMX: Don't reread VMCS-agnostic " Paolo Bonzini
2019-06-14 16:25   ` Sean Christopherson
2019-06-13 17:03 ` [PATCH 22/43] KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped Paolo Bonzini
2019-06-17 19:17   ` Radim Krčmář
2019-06-17 20:07     ` Sean Christopherson
2019-06-18  9:43       ` Paolo Bonzini
2019-06-13 17:03 ` [PATCH 23/43] KVM: nVMX: Don't speculatively write virtual-APIC page address Paolo Bonzini
2019-06-13 17:03 ` [PATCH 24/43] KVM: nVMX: Don't speculatively write APIC-access " Paolo Bonzini
2019-06-13 17:03 ` [PATCH 25/43] KVM: nVMX: Update vmcs12 for MSR_IA32_CR_PAT when it's written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 26/43] KVM: nVMX: Update vmcs12 for SYSENTER MSRs when they're written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 27/43] KVM: nVMX: Update vmcs12 for MSR_IA32_DEBUGCTLMSR when it's written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 28/43] KVM: nVMX: Don't update GUEST_BNDCFGS if it's clean in HV eVMCS Paolo Bonzini
2019-06-13 17:03 ` [PATCH 29/43] KVM: x86: introduce is_pae_paging Paolo Bonzini
2019-06-13 17:03 ` [PATCH 30/43] KVM: nVMX: Copy PDPTRs to/from vmcs12 only when necessary Paolo Bonzini
2019-06-13 17:03 ` [PATCH 31/43] KVM: nVMX: Use adjusted pin controls for vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 32/43] KVM: VMX: Add builder macros for shadowing controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 33/43] KVM: VMX: Shadow VMCS pin controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 34/43] KVM: VMX: Shadow VMCS primary execution controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 35/43] KVM: VMX: Shadow VMCS secondary " Paolo Bonzini
2019-06-13 17:03 ` [PATCH 36/43] KVM: nVMX: Shadow VMCS controls on a per-VMCS basis Paolo Bonzini
2019-06-13 17:03 ` [PATCH 37/43] KVM: nVMX: Don't reset VMCS controls shadow on VMCS switch Paolo Bonzini
2019-06-13 17:03 ` [PATCH 38/43] KVM: VMX: Explicitly initialize controls shadow at VMCS allocation Paolo Bonzini
2019-06-13 17:03 ` [PATCH 39/43] KVM: nVMX: Preserve last USE_MSR_BITMAPS when preparing vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 40/43] KVM: nVMX: Preset *DT exiting in vmcs02 when emulating UMIP Paolo Bonzini
2019-06-13 17:03 ` [PATCH 41/43] KVM: VMX: Drop hv_timer_armed from 'struct loaded_vmcs' Paolo Bonzini
2019-06-13 17:03 ` [PATCH 42/43] KVM: VMX: Leave preemption timer running when it's disabled Paolo Bonzini
2019-06-14 16:34   ` Sean Christopherson
2019-06-13 17:03 ` [PATCH 43/43] KVM: nVMX: shadow pin based execution controls Paolo Bonzini
2019-06-14 16:34   ` Sean Christopherson

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1560445409-17363-7-git-send-email-pbonzini@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=sean.j.christopherson@intel.com \
    --cc=vkuznets@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

KVM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvm/0 kvm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvm kvm/ https://lore.kernel.org/kvm \
		kvm@vger.kernel.org kvm@archiver.kernel.org
	public-inbox-index kvm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.kvm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox