The patch below does not apply to the 5.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 541e886f7972cc647804dbb4909189e67987a945 Mon Sep 17 00:00:00 2001
From: Wanpeng Li wanpengli@tencent.com Date: Fri, 17 May 2019 16:49:50 +0800 Subject: [PATCH] KVM: nVMX: Fix using __this_cpu_read() in preemptible context MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
BUG: using __this_cpu_read() in preemptible [00000000] code: qemu-system-x86/4590 caller is nested_vmx_enter_non_root_mode+0xebd/0x1790 [kvm_intel] CPU: 4 PID: 4590 Comm: qemu-system-x86 Tainted: G OE 5.1.0-rc4+ #1 Call Trace: dump_stack+0x67/0x95 __this_cpu_preempt_check+0xd2/0xe0 nested_vmx_enter_non_root_mode+0xebd/0x1790 [kvm_intel] nested_vmx_run+0xda/0x2b0 [kvm_intel] handle_vmlaunch+0x13/0x20 [kvm_intel] vmx_handle_exit+0xbd/0x660 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xa2c/0x1e50 [kvm] kvm_vcpu_ioctl+0x3ad/0x6d0 [kvm] do_vfs_ioctl+0xa5/0x6e0 ksys_ioctl+0x6d/0x80 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x6f/0x6c0 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Accessing per-cpu variable should disable preemption, this patch extends the preemption disable region for __this_cpu_read().
Cc: Paolo Bonzini pbonzini@redhat.com Cc: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Wanpeng Li wanpengli@tencent.com Fixes: 52017608da33 ("KVM: nVMX: add option to perform early consistency checks via H/W") Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson sean.j.christopherson@intel.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 6b450839c766..1032f068f0b9 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2784,14 +2784,13 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) : "cc", "memory" );
- preempt_enable(); - if (vmx->msr_autoload.host.nr) vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr); if (vmx->msr_autoload.guest.nr) vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
if (vm_fail) { + preempt_enable(); WARN_ON_ONCE(vmcs_read32(VM_INSTRUCTION_ERROR) != VMXERR_ENTRY_INVALID_CONTROL_FIELD); return 1; @@ -2803,6 +2802,7 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu) local_irq_enable(); if (hw_breakpoint_active()) set_debugreg(__this_cpu_read(cpu_dr7), 7); + preempt_enable();
/* * A non-failing VMEntry means we somehow entered guest mode with