From: Greg Kroah-Hartman Date: Mon, 17 May 2021 08:48:49 +0000 (+0200) Subject: 5.12-stable patches X-Git-Tag: v5.4.120~50 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=36e4d208a52f782f5f3e88f484e1395593e9c030;p=thirdparty%2Fkernel%2Fstable-queue.git 5.12-stable patches added patches: kvm-vmx-disable-preemption-when-probing-user-return-msrs.patch kvm-vmx-do-not-advertise-rdpid-if-enable_rdtscp-control-is-unsupported.patch --- diff --git a/queue-5.12/kvm-vmx-disable-preemption-when-probing-user-return-msrs.patch b/queue-5.12/kvm-vmx-disable-preemption-when-probing-user-return-msrs.patch new file mode 100644 index 00000000000..abb0c0dcd09 --- /dev/null +++ b/queue-5.12/kvm-vmx-disable-preemption-when-probing-user-return-msrs.patch @@ -0,0 +1,82 @@ +From 5104d7ffcf24749939bea7fdb5378d186473f890 Mon Sep 17 00:00:00 2001 +From: Sean Christopherson +Date: Tue, 4 May 2021 10:17:24 -0700 +Subject: KVM: VMX: Disable preemption when probing user return MSRs + +From: Sean Christopherson + +commit 5104d7ffcf24749939bea7fdb5378d186473f890 upstream. + +Disable preemption when probing a user return MSR via RDSMR/WRMSR. If +the MSR holds a different value per logical CPU, the WRMSR could corrupt +the host's value if KVM is preempted between the RDMSR and WRMSR, and +then rescheduled on a different CPU. + +Opportunistically land the helper in common x86, SVM will use the helper +in a future commit. + +Fixes: 4be534102624 ("KVM: VMX: Initialize vmx->guest_msrs[] right after allocation") +Cc: stable@vger.kernel.org +Cc: Xiaoyao Li +Signed-off-by: Sean Christopherson +Message-Id: <20210504171734.1434054-6-seanjc@google.com> +Reviewed-by: Jim Mattson +Signed-off-by: Paolo Bonzini +Signed-off-by: Greg Kroah-Hartman +--- + arch/x86/include/asm/kvm_host.h | 1 + + arch/x86/kvm/vmx/vmx.c | 5 +---- + arch/x86/kvm/x86.c | 16 ++++++++++++++++ + 3 files changed, 18 insertions(+), 4 deletions(-) + +--- a/arch/x86/include/asm/kvm_host.h ++++ b/arch/x86/include/asm/kvm_host.h +@@ -1753,6 +1753,7 @@ int kvm_pv_send_ipi(struct kvm *kvm, uns + unsigned long icr, int op_64_bit); + + void kvm_define_user_return_msr(unsigned index, u32 msr); ++int kvm_probe_user_return_msr(u32 msr); + int kvm_set_user_return_msr(unsigned index, u64 val, u64 mask); + + u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc); +--- a/arch/x86/kvm/vmx/vmx.c ++++ b/arch/x86/kvm/vmx/vmx.c +@@ -6914,12 +6914,9 @@ static int vmx_create_vcpu(struct kvm_vc + + for (i = 0; i < ARRAY_SIZE(vmx_uret_msrs_list); ++i) { + u32 index = vmx_uret_msrs_list[i]; +- u32 data_low, data_high; + int j = vmx->nr_uret_msrs; + +- if (rdmsr_safe(index, &data_low, &data_high) < 0) +- continue; +- if (wrmsr_safe(index, data_low, data_high) < 0) ++ if (kvm_probe_user_return_msr(index)) + continue; + + vmx->guest_uret_msrs[j].slot = i; +--- a/arch/x86/kvm/x86.c ++++ b/arch/x86/kvm/x86.c +@@ -335,6 +335,22 @@ static void kvm_on_user_return(struct us + } + } + ++int kvm_probe_user_return_msr(u32 msr) ++{ ++ u64 val; ++ int ret; ++ ++ preempt_disable(); ++ ret = rdmsrl_safe(msr, &val); ++ if (ret) ++ goto out; ++ ret = wrmsrl_safe(msr, val); ++out: ++ preempt_enable(); ++ return ret; ++} ++EXPORT_SYMBOL_GPL(kvm_probe_user_return_msr); ++ + void kvm_define_user_return_msr(unsigned slot, u32 msr) + { + BUG_ON(slot >= KVM_MAX_NR_USER_RETURN_MSRS); diff --git a/queue-5.12/kvm-vmx-do-not-advertise-rdpid-if-enable_rdtscp-control-is-unsupported.patch b/queue-5.12/kvm-vmx-do-not-advertise-rdpid-if-enable_rdtscp-control-is-unsupported.patch new file mode 100644 index 00000000000..91661125593 --- /dev/null +++ b/queue-5.12/kvm-vmx-do-not-advertise-rdpid-if-enable_rdtscp-control-is-unsupported.patch @@ -0,0 +1,42 @@ +From 8aec21c04caa2000f91cf8822ae0811e4b0c3971 Mon Sep 17 00:00:00 2001 +From: Sean Christopherson +Date: Tue, 4 May 2021 10:17:20 -0700 +Subject: KVM: VMX: Do not advertise RDPID if ENABLE_RDTSCP control is unsupported + +From: Sean Christopherson + +commit 8aec21c04caa2000f91cf8822ae0811e4b0c3971 upstream. + +Clear KVM's RDPID capability if the ENABLE_RDTSCP secondary exec control is +unsupported. Despite being enumerated in a separate CPUID flag, RDPID is +bundled under the same VMCS control as RDTSCP and will #UD in VMX non-root +if ENABLE_RDTSCP is not enabled. + +Fixes: 41cd02c6f7f6 ("kvm: x86: Expose RDPID in KVM_GET_SUPPORTED_CPUID") +Cc: stable@vger.kernel.org +Signed-off-by: Sean Christopherson +Message-Id: <20210504171734.1434054-2-seanjc@google.com> +Reviewed-by: Jim Mattson +Reviewed-by: Reiji Watanabe +Signed-off-by: Paolo Bonzini +Signed-off-by: Greg Kroah-Hartman +--- + arch/x86/kvm/vmx/vmx.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +--- a/arch/x86/kvm/vmx/vmx.c ++++ b/arch/x86/kvm/vmx/vmx.c +@@ -7352,9 +7352,11 @@ static __init void vmx_set_cpu_caps(void + if (!cpu_has_vmx_xsaves()) + kvm_cpu_cap_clear(X86_FEATURE_XSAVES); + +- /* CPUID 0x80000001 */ +- if (!cpu_has_vmx_rdtscp()) ++ /* CPUID 0x80000001 and 0x7 (RDPID) */ ++ if (!cpu_has_vmx_rdtscp()) { + kvm_cpu_cap_clear(X86_FEATURE_RDTSCP); ++ kvm_cpu_cap_clear(X86_FEATURE_RDPID); ++ } + + if (cpu_has_vmx_waitpkg()) + kvm_cpu_cap_check_and_set(X86_FEATURE_WAITPKG); diff --git a/queue-5.12/series b/queue-5.12/series index 0f7f72f68c7..00a2d412427 100644 --- a/queue-5.12/series +++ b/queue-5.12/series @@ -330,3 +330,5 @@ kvm-x86-emulate-rdpid-only-if-rdtscp-is-supported.patch kvm-x86-move-rdpid-emulation-intercept-to-its-own-enum.patch kvm-x86-add-support-for-rdpid-without-rdtscp.patch kvm-nvmx-always-make-an-attempt-to-map-evmcs-after-migration.patch +kvm-vmx-do-not-advertise-rdpid-if-enable_rdtscp-control-is-unsupported.patch +kvm-vmx-disable-preemption-when-probing-user-return-msrs.patch