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KVM: selftests: Expect #PF(RSVD) when TDP is disabled

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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: 39bbcc3a4e ("selftests: kvm: Allows userspace to handle emulation errors.")
Signed-off-by: David Matlack <dmatlack@google.com>
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 <seanjc@google.com>
This commit is contained in:
David Matlack
2022-11-02 11:46:53 -07:00
committed by Sean Christopherson
parent b9635930f0
commit a323845d6c
1 changed files with 46 additions and 5 deletions
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tools/testing/selftests/kvm/x86_64/smaller_maxphyaddr_emulation_test.c
+46 -5
View File
@@ -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);