From a323845d6c3d2f667274bde8145906580359fe06 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Wed, 2 Nov 2022 11:46:53 -0700 Subject: [PATCH] KVM: selftests: Expect #PF(RSVD) when TDP is disabled Change smaller_maxphyaddr_emulation_test to expect a #PF(RSVD), rather than an emulation failure, when TDP is disabled. KVM only needs to emulate instructions to emulate a smaller guest.MAXPHYADDR when TDP is enabled. Fixes: 39bbcc3a4e39 ("selftests: kvm: Allows userspace to handle emulation errors.") Signed-off-by: David Matlack Link: https://lore.kernel.org/r/20221102184654.282799-10-dmatlack@google.com [sean: massage comment to talk about having to emulate due to MAXPHYADDR] Signed-off-by: Sean Christopherson --- .../kvm/x86_64/smaller_maxphyaddr_emulation_test.c | 51 +++++++++++++++++++--- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c b/tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c index a8d0811..06edf00 100644 --- a/tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c +++ b/tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c @@ -21,9 +21,27 @@ #define MEM_REGION_SLOT 10 #define MEM_REGION_SIZE PAGE_SIZE -static void guest_code(void) +static void guest_code(bool tdp_enabled) { - flds(MEM_REGION_GVA); + uint64_t error_code; + uint64_t vector; + + vector = kvm_asm_safe_ec(FLDS_MEM_EAX, error_code, "a"(MEM_REGION_GVA)); + + /* + * When TDP is enabled, flds will trigger an emulation failure, exit to + * userspace, and then the selftest host "VMM" skips the instruction. + * + * When TDP is disabled, no instruction emulation is required so flds + * should generate #PF(RSVD). + */ + if (tdp_enabled) { + GUEST_ASSERT(!vector); + } else { + GUEST_ASSERT_EQ(vector, PF_VECTOR); + GUEST_ASSERT(error_code & PFERR_RSVD_MASK); + } + GUEST_DONE(); } @@ -31,6 +49,7 @@ int main(int argc, char *argv[]) { struct kvm_vcpu *vcpu; struct kvm_vm *vm; + struct ucall uc; uint64_t *pte; uint64_t *hva; uint64_t gpa; @@ -39,6 +58,10 @@ int main(int argc, char *argv[]) TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR)); vm = vm_create_with_one_vcpu(&vcpu, guest_code); + vcpu_args_set(vcpu, 1, kvm_is_tdp_enabled()); + + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); vcpu_set_cpuid_maxphyaddr(vcpu, MAXPHYADDR); @@ -60,9 +83,27 @@ int main(int argc, char *argv[]) *pte |= BIT_ULL(MAXPHYADDR); vcpu_run(vcpu); - handle_flds_emulation_failure_exit(vcpu); - vcpu_run(vcpu); - ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_DONE); + + /* + * When TDP is enabled, KVM must emulate in response the guest physical + * address that is illegal from the guest's perspective, but is legal + * from hardware's perspeective. This should result in an emulation + * failure exit to userspace since KVM doesn't support emulating flds. + */ + if (kvm_is_tdp_enabled()) { + handle_flds_emulation_failure_exit(vcpu); + vcpu_run(vcpu); + } + + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + break; + case UCALL_DONE: + break; + default: + TEST_FAIL("Unrecognized ucall: %lu\n", uc.cmd); + } kvm_vm_free(vm); -- 2.7.4