From 92ea908016eb667eda7694c97f9c9298b60d7bce Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 27 May 2021 11:24:34 +0200 Subject: [PATCH] 5.10-stable patches added patches: context_tracking-move-guest-exit-context-tracking-to-separate-helpers.patch context_tracking-move-guest-exit-vtime-accounting-to-separate-helpers.patch kvm-x86-defer-vtime-accounting-til-after-irq-handling.patch --- ...context-tracking-to-separate-helpers.patch | 52 ++++++++++ ...vtime-accounting-to-separate-helpers.patch | 73 ++++++++++++++ ...me-accounting-til-after-irq-handling.patch | 96 +++++++++++++++++++ queue-5.10/series | 3 + 4 files changed, 224 insertions(+) create mode 100644 queue-5.10/context_tracking-move-guest-exit-context-tracking-to-separate-helpers.patch create mode 100644 queue-5.10/context_tracking-move-guest-exit-vtime-accounting-to-separate-helpers.patch create mode 100644 queue-5.10/kvm-x86-defer-vtime-accounting-til-after-irq-handling.patch diff --git a/queue-5.10/context_tracking-move-guest-exit-context-tracking-to-separate-helpers.patch b/queue-5.10/context_tracking-move-guest-exit-context-tracking-to-separate-helpers.patch new file mode 100644 index 00000000000..6c2d812f1de --- /dev/null +++ b/queue-5.10/context_tracking-move-guest-exit-context-tracking-to-separate-helpers.patch @@ -0,0 +1,52 @@ +From 866a6dadbb027b2955a7ae00bab9705d382def12 Mon Sep 17 00:00:00 2001 +From: Wanpeng Li +Date: Tue, 4 May 2021 17:27:28 -0700 +Subject: context_tracking: Move guest exit context tracking to separate helpers + +From: Wanpeng Li + +commit 866a6dadbb027b2955a7ae00bab9705d382def12 upstream. + +Provide separate context tracking helpers for guest exit, the standalone +helpers will be called separately by KVM x86 in later patches to fix +tick-based accounting. + +Suggested-by: Thomas Gleixner +Signed-off-by: Wanpeng Li +Co-developed-by: Sean Christopherson +Signed-off-by: Sean Christopherson +Signed-off-by: Thomas Gleixner +Link: https://lore.kernel.org/r/20210505002735.1684165-2-seanjc@google.com +Signed-off-by: Greg Kroah-Hartman +--- + include/linux/context_tracking.h | 9 ++++++++- + 1 file changed, 8 insertions(+), 1 deletion(-) + +--- a/include/linux/context_tracking.h ++++ b/include/linux/context_tracking.h +@@ -129,10 +129,15 @@ static __always_inline void guest_enter_ + } + } + +-static __always_inline void guest_exit_irqoff(void) ++static __always_inline void context_tracking_guest_exit(void) + { + if (context_tracking_enabled()) + __context_tracking_exit(CONTEXT_GUEST); ++} ++ ++static __always_inline void guest_exit_irqoff(void) ++{ ++ context_tracking_guest_exit(); + + instrumentation_begin(); + if (vtime_accounting_enabled_this_cpu()) +@@ -157,6 +162,8 @@ static __always_inline void guest_enter_ + instrumentation_end(); + } + ++static __always_inline void context_tracking_guest_exit(void) { } ++ + static __always_inline void guest_exit_irqoff(void) + { + instrumentation_begin(); diff --git a/queue-5.10/context_tracking-move-guest-exit-vtime-accounting-to-separate-helpers.patch b/queue-5.10/context_tracking-move-guest-exit-vtime-accounting-to-separate-helpers.patch new file mode 100644 index 00000000000..cf823ae9ce4 --- /dev/null +++ b/queue-5.10/context_tracking-move-guest-exit-vtime-accounting-to-separate-helpers.patch @@ -0,0 +1,73 @@ +From 88d8220bbf06dd8045b2ac4be1046290eaa7773a Mon Sep 17 00:00:00 2001 +From: Wanpeng Li +Date: Tue, 4 May 2021 17:27:29 -0700 +Subject: context_tracking: Move guest exit vtime accounting to separate helpers + +From: Wanpeng Li + +commit 88d8220bbf06dd8045b2ac4be1046290eaa7773a upstream. + +Provide separate vtime accounting functions for guest exit instead of +open coding the logic within the context tracking code. This will allow +KVM x86 to handle vtime accounting slightly differently when using +tick-based accounting. + +Suggested-by: Thomas Gleixner +Signed-off-by: Wanpeng Li +Co-developed-by: Sean Christopherson +Signed-off-by: Sean Christopherson +Signed-off-by: Thomas Gleixner +Reviewed-by: Christian Borntraeger +Link: https://lore.kernel.org/r/20210505002735.1684165-3-seanjc@google.com +Signed-off-by: Greg Kroah-Hartman +--- + include/linux/context_tracking.h | 22 ++++++++++++++++------ + 1 file changed, 16 insertions(+), 6 deletions(-) + +--- a/include/linux/context_tracking.h ++++ b/include/linux/context_tracking.h +@@ -135,15 +135,20 @@ static __always_inline void context_trac + __context_tracking_exit(CONTEXT_GUEST); + } + +-static __always_inline void guest_exit_irqoff(void) ++static __always_inline void vtime_account_guest_exit(void) + { +- context_tracking_guest_exit(); +- +- instrumentation_begin(); + if (vtime_accounting_enabled_this_cpu()) + vtime_guest_exit(current); + else + current->flags &= ~PF_VCPU; ++} ++ ++static __always_inline void guest_exit_irqoff(void) ++{ ++ context_tracking_guest_exit(); ++ ++ instrumentation_begin(); ++ vtime_account_guest_exit(); + instrumentation_end(); + } + +@@ -164,12 +169,17 @@ static __always_inline void guest_enter_ + + static __always_inline void context_tracking_guest_exit(void) { } + ++static __always_inline void vtime_account_guest_exit(void) ++{ ++ vtime_account_kernel(current); ++ current->flags &= ~PF_VCPU; ++} ++ + static __always_inline void guest_exit_irqoff(void) + { + instrumentation_begin(); + /* Flush the guest cputime we spent on the guest */ +- vtime_account_kernel(current); +- current->flags &= ~PF_VCPU; ++ vtime_account_guest_exit(); + instrumentation_end(); + } + #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */ diff --git a/queue-5.10/kvm-x86-defer-vtime-accounting-til-after-irq-handling.patch b/queue-5.10/kvm-x86-defer-vtime-accounting-til-after-irq-handling.patch new file mode 100644 index 00000000000..0a8b99a0d81 --- /dev/null +++ b/queue-5.10/kvm-x86-defer-vtime-accounting-til-after-irq-handling.patch @@ -0,0 +1,96 @@ +From 160457140187c5fb127b844e5a85f87f00a01b14 Mon Sep 17 00:00:00 2001 +From: Wanpeng Li +Date: Tue, 4 May 2021 17:27:30 -0700 +Subject: KVM: x86: Defer vtime accounting 'til after IRQ handling + +From: Wanpeng Li + +commit 160457140187c5fb127b844e5a85f87f00a01b14 upstream. + +Defer the call to account guest time until after servicing any IRQ(s) +that happened in the guest or immediately after VM-Exit. Tick-based +accounting of vCPU time relies on PF_VCPU being set when the tick IRQ +handler runs, and IRQs are blocked throughout the main sequence of +vcpu_enter_guest(), including the call into vendor code to actually +enter and exit the guest. + +This fixes a bug where reported guest time remains '0', even when +running an infinite loop in the guest: + + https://bugzilla.kernel.org/show_bug.cgi?id=209831 + +Fixes: 87fa7f3e98a131 ("x86/kvm: Move context tracking where it belongs") +Suggested-by: Thomas Gleixner +Co-developed-by: Sean Christopherson +Signed-off-by: Wanpeng Li +Signed-off-by: Sean Christopherson +Signed-off-by: Thomas Gleixner +Cc: stable@vger.kernel.org +Link: https://lore.kernel.org/r/20210505002735.1684165-4-seanjc@google.com +Signed-off-by: Greg Kroah-Hartman +--- + arch/x86/kvm/svm/svm.c | 6 +++--- + arch/x86/kvm/vmx/vmx.c | 6 +++--- + arch/x86/kvm/x86.c | 9 +++++++++ + 3 files changed, 15 insertions(+), 6 deletions(-) + +--- a/arch/x86/kvm/svm/svm.c ++++ b/arch/x86/kvm/svm/svm.c +@@ -3532,15 +3532,15 @@ static noinstr void svm_vcpu_enter_exit( + * 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. ++ * context_tracking_guest_exit() 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(); ++ context_tracking_guest_exit(); + + instrumentation_begin(); + trace_hardirqs_off_finish(); +--- a/arch/x86/kvm/vmx/vmx.c ++++ b/arch/x86/kvm/vmx/vmx.c +@@ -6640,15 +6640,15 @@ static noinstr void vmx_vcpu_enter_exit( + * 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. ++ * context_tracking_guest_exit() 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(); ++ context_tracking_guest_exit(); + + instrumentation_begin(); + trace_hardirqs_off_finish(); +--- a/arch/x86/kvm/x86.c ++++ b/arch/x86/kvm/x86.c +@@ -9063,6 +9063,15 @@ static int vcpu_enter_guest(struct kvm_v + local_irq_disable(); + kvm_after_interrupt(vcpu); + ++ /* ++ * Wait until after servicing IRQs to account guest time so that any ++ * ticks that occurred while running the guest are properly accounted ++ * to the guest. Waiting until IRQs are enabled degrades the accuracy ++ * of accounting via context tracking, but the loss of accuracy is ++ * acceptable for all known use cases. ++ */ ++ vtime_account_guest_exit(); ++ + if (lapic_in_kernel(vcpu)) { + s64 delta = vcpu->arch.apic->lapic_timer.advance_expire_delta; + if (delta != S64_MIN) { diff --git a/queue-5.10/series b/queue-5.10/series index fe2006fd888..b483908309d 100644 --- a/queue-5.10/series +++ b/queue-5.10/series @@ -1,3 +1,6 @@ bpf-wrap-aux-data-inside-bpf_sanitize_info-container.patch bpf-fix-mask-direction-swap-upon-off-reg-sign-change.patch bpf-no-need-to-simulate-speculative-domain-for-immediates.patch +context_tracking-move-guest-exit-context-tracking-to-separate-helpers.patch +context_tracking-move-guest-exit-vtime-accounting-to-separate-helpers.patch +kvm-x86-defer-vtime-accounting-til-after-irq-handling.patch -- 2.47.3