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Message-Id: <20210413182933.1046389-7-seanjc@google.com>
Date: Tue, 13 Apr 2021 11:29:32 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>
Cc: Sean Christopherson <seanjc@...gle.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
Christian Borntraeger <borntraeger@...ibm.com>,
Michael Tokarev <mjt@....msk.ru>
Subject: [RFC PATCH 6/7] KVM: x86: Consolidate guest enter/exit logic to
common helpers
Move the enter/exit logic in {svm,vmx}_vcpu_enter_exit() to common
helpers. In addition to deduplicating code, this will allow tweaking the
vtime accounting in the VM-Exit path without splitting logic across x86,
VMX, and SVM.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
arch/x86/kvm/svm/svm.c | 39 ++----------------------------------
arch/x86/kvm/vmx/vmx.c | 39 ++----------------------------------
arch/x86/kvm/x86.h | 45 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+), 74 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 48b396f33bee..0677595d07e5 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3713,25 +3713,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- /*
- * VMENTER enables interrupts (host state), but the kernel state is
- * interrupts disabled when this is invoked. Also tell RCU about
- * it. This is the same logic as for exit_to_user_mode().
- *
- * This ensures that e.g. latency analysis on the host observes
- * guest mode as interrupt enabled.
- *
- * guest_enter_irqoff() informs context tracking about the
- * transition to guest mode and if enabled adjusts RCU state
- * accordingly.
- */
- instrumentation_begin();
- trace_hardirqs_on_prepare();
- lockdep_hardirqs_on_prepare(CALLER_ADDR0);
- instrumentation_end();
-
- guest_enter_irqoff();
- lockdep_hardirqs_on(CALLER_ADDR0);
+ kvm_guest_enter_irqoff();
if (sev_es_guest(vcpu->kvm)) {
__svm_sev_es_vcpu_run(svm->vmcb_pa);
@@ -3745,24 +3727,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
vmload(__sme_page_pa(sd->save_area));
}
- /*
- * VMEXIT disables interrupts (host state), but tracing and lockdep
- * have them in state 'on' as recorded before entering guest mode.
- * Same as enter_from_user_mode().
- *
- * guest_exit_irqoff() restores host context and reinstates RCU if
- * enabled and required.
- *
- * This needs to be done before the below as native_read_msr()
- * contains a tracepoint and x86_spec_ctrl_restore_host() calls
- * into world and some more.
- */
- lockdep_hardirqs_off(CALLER_ADDR0);
- guest_exit_irqoff();
-
- instrumentation_begin();
- trace_hardirqs_off_finish();
- instrumentation_end();
+ kvm_guest_exit_irqoff();
}
static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c05e6e2854b5..19b0e25bf598 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6600,25 +6600,7 @@ static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
struct vcpu_vmx *vmx)
{
- /*
- * VMENTER enables interrupts (host state), but the kernel state is
- * interrupts disabled when this is invoked. Also tell RCU about
- * it. This is the same logic as for exit_to_user_mode().
- *
- * This ensures that e.g. latency analysis on the host observes
- * guest mode as interrupt enabled.
- *
- * guest_enter_irqoff() informs context tracking about the
- * transition to guest mode and if enabled adjusts RCU state
- * accordingly.
- */
- instrumentation_begin();
- trace_hardirqs_on_prepare();
- lockdep_hardirqs_on_prepare(CALLER_ADDR0);
- instrumentation_end();
-
- guest_enter_irqoff();
- lockdep_hardirqs_on(CALLER_ADDR0);
+ kvm_guest_enter_irqoff();
/* L1D Flush includes CPU buffer clear to mitigate MDS */
if (static_branch_unlikely(&vmx_l1d_should_flush))
@@ -6634,24 +6616,7 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
vcpu->arch.cr2 = native_read_cr2();
- /*
- * VMEXIT disables interrupts (host state), but tracing and lockdep
- * have them in state 'on' as recorded before entering guest mode.
- * Same as enter_from_user_mode().
- *
- * guest_exit_irqoff() restores host context and reinstates RCU if
- * enabled and required.
- *
- * This needs to be done before the below as native_read_msr()
- * contains a tracepoint and x86_spec_ctrl_restore_host() calls
- * into world and some more.
- */
- lockdep_hardirqs_off(CALLER_ADDR0);
- guest_exit_irqoff();
-
- instrumentation_begin();
- trace_hardirqs_off_finish();
- instrumentation_end();
+ kvm_guest_exit_irqoff();
}
static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index daccf20fbcd5..74ef92f47db8 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -8,6 +8,51 @@
#include "kvm_cache_regs.h"
#include "kvm_emulate.h"
+static __always_inline void kvm_guest_enter_irqoff(void)
+{
+ /*
+ * VMENTER enables interrupts (host state), but the kernel state is
+ * interrupts disabled when this is invoked. Also tell RCU about
+ * it. This is the same logic as for exit_to_user_mode().
+ *
+ * This ensures that e.g. latency analysis on the host observes
+ * guest mode as interrupt enabled.
+ *
+ * guest_enter_irqoff() informs context tracking about the
+ * transition to guest mode and if enabled adjusts RCU state
+ * accordingly.
+ */
+ instrumentation_begin();
+ trace_hardirqs_on_prepare();
+ lockdep_hardirqs_on_prepare(CALLER_ADDR0);
+ instrumentation_end();
+
+ guest_enter_irqoff();
+ lockdep_hardirqs_on(CALLER_ADDR0);
+}
+
+static __always_inline void kvm_guest_exit_irqoff(void)
+{
+ /*
+ * VMEXIT disables interrupts (host state), but tracing and lockdep
+ * have them in state 'on' as recorded before entering guest mode.
+ * Same as enter_from_user_mode().
+ *
+ * guest_exit_irqoff() restores host context and reinstates RCU if
+ * enabled and required.
+ *
+ * This needs to be done before the below as native_read_msr()
+ * contains a tracepoint and x86_spec_ctrl_restore_host() calls
+ * into world and some more.
+ */
+ lockdep_hardirqs_off(CALLER_ADDR0);
+ guest_exit_irqoff();
+
+ instrumentation_begin();
+ trace_hardirqs_off_finish();
+ instrumentation_end();
+}
+
#define KVM_NESTED_VMENTER_CONSISTENCY_CHECK(consistency_check) \
({ \
bool failed = (consistency_check); \
--
2.31.1.295.g9ea45b61b8-goog
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