From: Greg Kroah-Hartman Date: Fri, 23 Feb 2018 16:23:22 +0000 (+0100) Subject: 4.9-stable patches X-Git-Tag: v3.18.96~12 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b0537f4e872a26925b3eb39f736e5e7bcee128f7;p=thirdparty%2Fkernel%2Fstable-queue.git 4.9-stable patches added patches: kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch --- diff --git a/queue-4.9/kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch b/queue-4.9/kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch new file mode 100644 index 00000000000..0ade9b7ba73 --- /dev/null +++ b/queue-4.9/kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch @@ -0,0 +1,102 @@ +From 9a6e7c39810e4a8bc7fc95056cefb40583fe07ef Mon Sep 17 00:00:00 2001 +From: Wanpeng Li +Date: Thu, 14 Sep 2017 03:54:16 -0700 +Subject: KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +From: Wanpeng Li + +commit 9a6e7c39810e4a8bc7fc95056cefb40583fe07ef upstream. + +qemu-system-x86-8600 [004] d..1 7205.687530: kvm_entry: vcpu 2 +qemu-system-x86-8600 [004] .... 7205.687532: kvm_exit: reason EXCEPTION_NMI rip 0xffffffffa921297d info ffffeb2c0e44e018 80000b0e +qemu-system-x86-8600 [004] .... 7205.687532: kvm_page_fault: address ffffeb2c0e44e018 error_code 0 +qemu-system-x86-8600 [004] .... 7205.687620: kvm_try_async_get_page: gva = 0xffffeb2c0e44e018, gfn = 0x427e4e +qemu-system-x86-8600 [004] .N.. 7205.687628: kvm_async_pf_not_present: token 0x8b002 gva 0xffffeb2c0e44e018 + kworker/4:2-7814 [004] .... 7205.687655: kvm_async_pf_completed: gva 0xffffeb2c0e44e018 address 0x7fcc30c4e000 +qemu-system-x86-8600 [004] .... 7205.687703: kvm_async_pf_ready: token 0x8b002 gva 0xffffeb2c0e44e018 +qemu-system-x86-8600 [004] d..1 7205.687711: kvm_entry: vcpu 2 + +After running some memory intensive workload in guest, I catch the kworker +which completes the GUP too quickly, and queues an "Page Ready" #PF exception +after the "Page not Present" exception before the next vmentry as the above +trace which will result in #DF injected to guest. + +This patch fixes it by clearing the queue for "Page not Present" if "Page Ready" +occurs before the next vmentry since the GUP has already got the required page +and shadow page table has already been fixed by "Page Ready" handler. + +Cc: Paolo Bonzini +Cc: Radim Krčmář +Signed-off-by: Wanpeng Li +Fixes: 7c90705bf2a3 ("KVM: Inject asynchronous page fault into a PV guest if page is swapped out.") +[Changed indentation and added clearing of injected. - Radim] +Signed-off-by: Radim Krčmář +[port from upstream v4.14-rc1, Don't assign to kvm_queued_exception::injected or + x86_exception::async_page_fault] +Signed-off-by: Jack Wang +Signed-off-by: Greg Kroah-Hartman + +--- + arch/x86/kvm/x86.c | 34 ++++++++++++++++++++++++++-------- + 1 file changed, 26 insertions(+), 8 deletions(-) + +--- a/arch/x86/kvm/x86.c ++++ b/arch/x86/kvm/x86.c +@@ -8427,6 +8427,13 @@ static int apf_put_user(struct kvm_vcpu + sizeof(val)); + } + ++static int apf_get_user(struct kvm_vcpu *vcpu, u32 *val) ++{ ++ ++ return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, val, ++ sizeof(u32)); ++} ++ + void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu, + struct kvm_async_pf *work) + { +@@ -8453,6 +8460,7 @@ void kvm_arch_async_page_present(struct + struct kvm_async_pf *work) + { + struct x86_exception fault; ++ u32 val; + + if (work->wakeup_all) + work->arch.token = ~0; /* broadcast wakeup */ +@@ -8460,14 +8468,24 @@ void kvm_arch_async_page_present(struct + kvm_del_async_pf_gfn(vcpu, work->arch.gfn); + trace_kvm_async_pf_ready(work->arch.token, work->gva); + +- if ((vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) && +- !apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) { +- fault.vector = PF_VECTOR; +- fault.error_code_valid = true; +- fault.error_code = 0; +- fault.nested_page_fault = false; +- fault.address = work->arch.token; +- kvm_inject_page_fault(vcpu, &fault); ++ if (vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED && ++ !apf_get_user(vcpu, &val)) { ++ if (val == KVM_PV_REASON_PAGE_NOT_PRESENT && ++ vcpu->arch.exception.pending && ++ vcpu->arch.exception.nr == PF_VECTOR && ++ !apf_put_user(vcpu, 0)) { ++ vcpu->arch.exception.pending = false; ++ vcpu->arch.exception.nr = 0; ++ vcpu->arch.exception.has_error_code = false; ++ vcpu->arch.exception.error_code = 0; ++ } else if (!apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) { ++ fault.vector = PF_VECTOR; ++ fault.error_code_valid = true; ++ fault.error_code = 0; ++ fault.nested_page_fault = false; ++ fault.address = work->arch.token; ++ kvm_inject_page_fault(vcpu, &fault); ++ } + } + vcpu->arch.apf.halted = false; + vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; diff --git a/queue-4.9/series b/queue-4.9/series index 20193e831f0..600ba0bae9c 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -139,3 +139,4 @@ idle-i7300-add-pci-dependency.patch arm64-fix-warning-about-swapper_pg_dir-overflow.patch usb-phy-msm-add-regulator-dependency.patch x86-microcode-amd-change-load_microcode_amd-s-param-to-bool-to-fix-preemptibility-bug.patch +kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch