This is a note to let you know that I've just added the patch titled

KVM: nVMX: Fix vmx_check_nested_events() return value in case an event was reinjected to L2

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kvm-nvmx-fix-vmx_check_nested_events-return-value-in-case-an-event-was-reinjected-to-l2.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Feb 1 13:45:42 CET 2018

From: Liran Alon liran.alon@oracle.com Date: Sun, 5 Nov 2017 16:07:43 +0200 Subject: KVM: nVMX: Fix vmx_check_nested_events() return value in case an event was reinjected to L2

From: Liran Alon liran.alon@oracle.com

[ Upstream commit 917dc6068bc12a2dafffcf0e9d405ddb1b8780cb ]

vmx_check_nested_events() should return -EBUSY only in case there is a pending L1 event which requires a VMExit from L2 to L1 but such a VMExit is currently blocked. Such VMExits are blocked either because nested_run_pending=1 or an event was reinjected to L2. vmx_check_nested_events() should return 0 in case there are no pending L1 events which requires a VMExit from L2 to L1 or if a VMExit from L2 to L1 was done internally.

However, upstream commit which introduced blocking in case an event was reinjected to L2 (commit acc9ab601327 ("KVM: nVMX: Fix pending events injection")) contains a bug: It returns -EBUSY even if there are no pending L1 events which requires VMExit from L2 to L1.

This commit fix this issue.

Fixes: acc9ab601327 ("KVM: nVMX: Fix pending events injection")

Signed-off-by: Liran Alon liran.alon@oracle.com Reviewed-by: Nikita Leshenko nikita.leshchenko@oracle.com Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/vmx.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)

--- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -11114,13 +11114,12 @@ static int vmx_check_nested_events(struc { struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long exit_qual; - - if (kvm_event_needs_reinjection(vcpu)) - return -EBUSY; + bool block_nested_events = + vmx->nested.nested_run_pending || kvm_event_needs_reinjection(vcpu);

if (vcpu->arch.exception.pending && nested_vmx_check_exception(vcpu, &exit_qual)) { - if (vmx->nested.nested_run_pending) + if (block_nested_events) return -EBUSY; nested_vmx_inject_exception_vmexit(vcpu, exit_qual); vcpu->arch.exception.pending = false; @@ -11129,14 +11128,14 @@ static int vmx_check_nested_events(struc

if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) && vmx->nested.preemption_timer_expired) { - if (vmx->nested.nested_run_pending) + if (block_nested_events) return -EBUSY; nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0); return 0; }

if (vcpu->arch.nmi_pending && nested_exit_on_nmi(vcpu)) { - if (vmx->nested.nested_run_pending) + if (block_nested_events) return -EBUSY; nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI, NMI_VECTOR | INTR_TYPE_NMI_INTR | @@ -11152,7 +11151,7 @@ static int vmx_check_nested_events(struc

if ((kvm_cpu_has_interrupt(vcpu) || external_intr) && nested_exit_on_intr(vcpu)) { - if (vmx->nested.nested_run_pending) + if (block_nested_events) return -EBUSY; nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0); return 0;

Patches currently in stable-queue which might be from liran.alon@oracle.com are

queue-4.14/kvm-nvmx-fix-vmx_check_nested_events-return-value-in-case-an-event-was-reinjected-to-l2.patch queue-4.14/kvm-x86-don-t-re-execute-instruction-when-not-passing-cr2-value.patch queue-4.14/kvm-x86-ioapic-preserve-read-only-values-in-the-redirection-table.patch queue-4.14/kvm-x86-ioapic-fix-level-triggered-eoi-and-ioapic-reconfigure-race.patch queue-4.14/kvm-x86-emulator-return-to-user-mode-on-l1-cpl-0-emulation-failure.patch queue-4.14/kvm-nvmx-nsvm-don-t-intercept-ud-when-running-l2.patch queue-4.14/kvm-x86-ioapic-clear-remote-irr-when-entry-is-switched-to-edge-triggered.patch