From a867e9d0cc15039a6ef72e17e2603303dcd1783f Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Thu, 17 Feb 2022 10:12:42 +0000 Subject: [PATCH 1/2] KVM: arm64: Don't miss pending interrupts for suspended vCPU In order to properly emulate the WFI instruction, KVM reads back ICH_VMCR_EL2 and enables doorbells for GICv4. These preparations are necessary in order to recognize pending interrupts in kvm_arch_vcpu_runnable() and return to the guest. Until recently, this work was done by kvm_arch_vcpu_{blocking,unblocking}(). Since commit 6109c5a6ab7f ("KVM: arm64: Move vGIC v4 handling for WFI out arch callback hook"), these callbacks were gutted and superseded by kvm_vcpu_wfi(). It is important to note that KVM implements PSCI CPU_SUSPEND calls as a WFI within the guest. However, the implementation calls directly into kvm_vcpu_halt(), which skips the needed work done in kvm_vcpu_wfi() to detect pending interrupts. Fix the issue by calling the WFI helper. Fixes: 6109c5a6ab7f ("KVM: arm64: Move vGIC v4 handling for WFI out arch callback hook") Signed-off-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220217101242.3013716-1-oupton@google.com --- arch/arm64/kvm/psci.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 3eae32876897c..2ce60fecd8619 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -46,8 +46,7 @@ static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) * specification (ARM DEN 0022A). This means all suspend states * for KVM will preserve the register state. */ - kvm_vcpu_halt(vcpu); - kvm_clear_request(KVM_REQ_UNHALT, vcpu); + kvm_vcpu_wfi(vcpu); return PSCI_RET_SUCCESS; } From 456f89e0928ab938122a40e9f094a6524cc158b4 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 23 Feb 2022 13:16:24 +0000 Subject: [PATCH 2/2] KVM: selftests: aarch64: Skip tests if we can't create a vgic-v3 The arch_timer and vgic_irq kselftests assume that they can create a vgic-v3, using the library function vgic_v3_setup() which aborts with a test failure if it is not possible to do so. Since vgic-v3 can only be instantiated on systems where the host has GICv3 this leads to false positives on older systems where that is not the case. Fix this by changing vgic_v3_setup() to return an error if the vgic can't be instantiated and have the callers skip if this happens. We could also exit flagging a skip in vgic_v3_setup() but this would prevent future test cases conditionally deciding which GIC to use or generally doing more complex output. Signed-off-by: Mark Brown Reviewed-by: Andrew Jones Tested-by: Ricardo Koller Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220223131624.1830351-1-broonie@kernel.org --- tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++- tools/testing/selftests/kvm/aarch64/vgic_irq.c | 4 ++++ tools/testing/selftests/kvm/lib/aarch64/vgic.c | 4 +++- 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c index 9ad38bd360a42..b08d30bf71c51 100644 --- a/tools/testing/selftests/kvm/aarch64/arch_timer.c +++ b/tools/testing/selftests/kvm/aarch64/arch_timer.c @@ -366,6 +366,7 @@ static struct kvm_vm *test_vm_create(void) { struct kvm_vm *vm; unsigned int i; + int ret; int nr_vcpus = test_args.nr_vcpus; vm = vm_create_default_with_vcpus(nr_vcpus, 0, 0, guest_code, NULL); @@ -382,7 +383,11 @@ static struct kvm_vm *test_vm_create(void) ucall_init(vm, NULL); test_init_timer_irq(vm); - vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA); + ret = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA); + if (ret < 0) { + print_skip("Failed to create vgic-v3"); + exit(KSFT_SKIP); + } /* Make all the test's cmdline args visible to the guest */ sync_global_to_guest(vm, test_args); diff --git a/tools/testing/selftests/kvm/aarch64/vgic_irq.c b/tools/testing/selftests/kvm/aarch64/vgic_irq.c index e6c7d7f8fbd1b..7eca977999170 100644 --- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c +++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c @@ -761,6 +761,10 @@ static void test_vgic(uint32_t nr_irqs, bool level_sensitive, bool eoi_split) gic_fd = vgic_v3_setup(vm, 1, nr_irqs, GICD_BASE_GPA, GICR_BASE_GPA); + if (gic_fd < 0) { + print_skip("Failed to create vgic-v3, skipping"); + exit(KSFT_SKIP); + } vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handlers[args.eoi_split][args.level_sensitive]); diff --git a/tools/testing/selftests/kvm/lib/aarch64/vgic.c b/tools/testing/selftests/kvm/lib/aarch64/vgic.c index b3a0fca0d7806..f5cd0c536d85c 100644 --- a/tools/testing/selftests/kvm/lib/aarch64/vgic.c +++ b/tools/testing/selftests/kvm/lib/aarch64/vgic.c @@ -52,7 +52,9 @@ int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus, uint32_t nr_irqs, nr_vcpus, nr_vcpus_created); /* Distributor setup */ - gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false); + if (_kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, + false, &gic_fd) != 0) + return -1; kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS, 0, &nr_irqs, true);