[v2,6/6] KVM: selftests: Test Hyper-V extended hypercall exit to userspace
Commit Message
Hyper-V extended hypercalls by default exit to userspace. Verify
userspace gets the call, update the result and then verify in guest
correct result is received.
Signed-off-by: Vipin Sharma <vipinsh@google.com>
---
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/include/x86_64/processor.h | 3 +
.../kvm/x86_64/hyperv_extended_hypercalls.c | 94 +++++++++++++++++++
4 files changed, 99 insertions(+)
create mode 100644 tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
Comments
Vipin Sharma <vipinsh@google.com> writes:
> Hyper-V extended hypercalls by default exit to userspace. Verify
> userspace gets the call, update the result and then verify in guest
> correct result is received.
>
> Signed-off-by: Vipin Sharma <vipinsh@google.com>
> ---
> tools/testing/selftests/kvm/.gitignore | 1 +
> tools/testing/selftests/kvm/Makefile | 1 +
> .../selftests/kvm/include/x86_64/processor.h | 3 +
> .../kvm/x86_64/hyperv_extended_hypercalls.c | 94 +++++++++++++++++++
> 4 files changed, 99 insertions(+)
> create mode 100644 tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
>
> diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
> index 082855d94c72..b17874697d74 100644
> --- a/tools/testing/selftests/kvm/.gitignore
> +++ b/tools/testing/selftests/kvm/.gitignore
> @@ -24,6 +24,7 @@
> /x86_64/hyperv_clock
> /x86_64/hyperv_cpuid
> /x86_64/hyperv_evmcs
> +/x86_64/hyperv_extended_hypercalls
My personal preference would be to shorten the name to something like
"hyperv_ext_hcalls", doesn't seem to be ambiguos. No strong preference
though, feel free to keep the long version.
> /x86_64/hyperv_features
> /x86_64/hyperv_ipi
> /x86_64/hyperv_svm_test
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index 2275ba861e0e..a0e12f5d9835 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -87,6 +87,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/fix_hypercall_test
> TEST_GEN_PROGS_x86_64 += x86_64/hyperv_clock
> TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
> TEST_GEN_PROGS_x86_64 += x86_64/hyperv_evmcs
> +TEST_GEN_PROGS_x86_64 += x86_64/hyperv_extended_hypercalls
> TEST_GEN_PROGS_x86_64 += x86_64/hyperv_features
> TEST_GEN_PROGS_x86_64 += x86_64/hyperv_ipi
> TEST_GEN_PROGS_x86_64 += x86_64/hyperv_svm_test
> diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
> index 5d310abe6c3f..f167396b887b 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/processor.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
> @@ -168,6 +168,9 @@ struct kvm_x86_cpu_feature {
> #define X86_FEATURE_KVM_HC_MAP_GPA_RANGE KVM_X86_CPU_FEATURE(0x40000001, 0, EAX, 16)
> #define X86_FEATURE_KVM_MIGRATION_CONTROL KVM_X86_CPU_FEATURE(0x40000001, 0, EAX, 17)
>
> +/* Hyper-V defined paravirt features */
> +#define X86_FEATURE_HYPERV_EXTENDED_HYPERCALLS KVM_X86_CPU_FEATURE(0x40000003, 0, EBX, 20)
> +
I completely forgot about my other series where I've converted the whole
hyperv_features test to using KVM_X86_CPU_FEATURE():
https://lore.kernel.org/kvm/20221013095849.705943-6-vkuznets@redhat.com/
but your define reminded me of it, thanks! Hope the whole thing will get
queued soon.
As for your change, I think it is better suited for
include/x86_64/hyperv.h instead of include/x86_64/processor.h anyway,
I'm trying to keep all Hyper-V related stuff separate as Hyper-V CPUID
leaves intersect with KVM's, e.g. 0x40000001.
> /*
> * Same idea as X86_FEATURE_XXX, but X86_PROPERTY_XXX retrieves a multi-bit
> * value/property as opposed to a single-bit feature. Again, pack the info
> diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c b/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
> new file mode 100644
> index 000000000000..13c1b03294a4
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
> @@ -0,0 +1,94 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Test Hyper-V extended hypercall, HV_EXT_CALL_QUERY_CAPABILITIES (0x8001),
> + * exit to userspace and receive result in guest.
> + *
> + * Negative tests are present in hyperv_features.c
> + *
> + * Copyright 2022 Google LLC
> + * Author: Vipin Sharma <vipinsh@google.com>
> + */
> +
> +#include "kvm_util.h"
> +#include "processor.h"
> +#include "hyperv.h"
> +
> +/* Any value is fine */
> +#define EXT_CAPABILITIES 0xbull
> +
> +static void guest_code(vm_vaddr_t in_pg_gpa, vm_vaddr_t out_pg_gpa,
> + vm_vaddr_t out_pg_gva)
> +{
> + uint64_t *output_gva;
> +
> + wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
> + wrmsr(HV_X64_MSR_HYPERCALL, in_pg_gpa);
> +
> + output_gva = (uint64_t *)out_pg_gva;
> +
> + hyperv_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, in_pg_gpa, out_pg_gpa);
> +
> + /* TLFS states output will be a uint64_t value */
> + GUEST_ASSERT_EQ(*output_gva, EXT_CAPABILITIES);
> +
> + GUEST_DONE();
> +}
> +
> +int main(void)
> +{
> + vm_vaddr_t hcall_out_page;
> + vm_vaddr_t hcall_in_page;
> + struct kvm_vcpu *vcpu;
> + struct kvm_run *run;
> + struct kvm_vm *vm;
> + uint64_t *outval;
> + struct ucall uc;
> +
> + /* Verify if extended hypercalls are supported */
> + if (!kvm_cpuid_has(kvm_get_supported_hv_cpuid(),
> + X86_FEATURE_HYPERV_EXTENDED_HYPERCALLS)) {
> + print_skip("Extended calls not supported by the kernel");
> + exit(KSFT_SKIP);
> + }
> +
> + vm = vm_create_with_one_vcpu(&vcpu, guest_code);
> + run = vcpu->run;
> + vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_ENFORCE_CPUID, 1);
Do we need this enforcement assuming we have no plans to add 'negative'
tests here (hyperv_features does it just fine)? vcpu_set_hv_cpuid()
enables everything anyway...
> + vcpu_set_hv_cpuid(vcpu);
> +
> + /* Hypercall input */
> + hcall_in_page = vm_vaddr_alloc_pages(vm, 1);
> + memset(addr_gva2hva(vm, hcall_in_page), 0x0, vm->page_size);
> +
> + /* Hypercall output */
> + hcall_out_page = vm_vaddr_alloc_pages(vm, 1);
> + memset(addr_gva2hva(vm, hcall_out_page), 0x0, vm->page_size);
> +
> + vcpu_args_set(vcpu, 3, addr_gva2gpa(vm, hcall_in_page),
> + addr_gva2gpa(vm, hcall_out_page), hcall_out_page);
> +
> + vcpu_run(vcpu);
> +
> + ASSERT_EXIT_REASON(vcpu, KVM_EXIT_HYPERV);
> +
> + outval = addr_gpa2hva(vm, run->hyperv.u.hcall.params[1]);
> + *outval = EXT_CAPABILITIES;
> + run->hyperv.u.hcall.result = HV_STATUS_SUCCESS;
> +
> + vcpu_run(vcpu);
> +
> + ASSERT_EXIT_REASON(vcpu, KVM_EXIT_IO);
> +
> + switch (get_ucall(vcpu, &uc)) {
> + case UCALL_ABORT:
> + REPORT_GUEST_ASSERT_2(uc, "arg1 = %ld, arg2 = %ld");
> + break;
> + case UCALL_DONE:
> + break;
> + default:
> + TEST_FAIL("Unhandled ucall: %ld", uc.cmd);
> + }
> +
> + kvm_vm_free(vm);
> + return 0;
> +}
On Tue, Nov 22, 2022 at 7:57 AM Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
>
> Vipin Sharma <vipinsh@google.com> writes:
>
> > index 082855d94c72..b17874697d74 100644
> > --- a/tools/testing/selftests/kvm/.gitignore
> > +++ b/tools/testing/selftests/kvm/.gitignore
> > @@ -24,6 +24,7 @@
> > /x86_64/hyperv_clock
> > /x86_64/hyperv_cpuid
> > /x86_64/hyperv_evmcs
> > +/x86_64/hyperv_extended_hypercalls
>
> My personal preference would be to shorten the name to something like
> "hyperv_ext_hcalls", doesn't seem to be ambiguos. No strong preference
> though, feel free to keep the long version.
>
I will keep the long one, in v1 David was suggesting it will be easier
for non Hyperv developers to read and understand.
> > +/* Hyper-V defined paravirt features */
> > +#define X86_FEATURE_HYPERV_EXTENDED_HYPERCALLS KVM_X86_CPU_FEATURE(0x40000003, 0, EBX, 20)
> > +
>
> I completely forgot about my other series where I've converted the whole
> hyperv_features test to using KVM_X86_CPU_FEATURE():
> https://lore.kernel.org/kvm/20221013095849.705943-6-vkuznets@redhat.com/
>
> but your define reminded me of it, thanks! Hope the whole thing will get
> queued soon.
>
Your patches are always one step ahead of me :D
If your series doesn't show up in the KVM queue soon, I will rebase my
patch series on top of your series
> As for your change, I think it is better suited for
> include/x86_64/hyperv.h instead of include/x86_64/processor.h anyway,
> I'm trying to keep all Hyper-V related stuff separate as Hyper-V CPUID
> leaves intersect with KVM's, e.g. 0x40000001.
>
Sounds good.
> > /*
> > * Same idea as X86_FEATURE_XXX, but X86_PROPERTY_XXX retrieves a multi-bit
> > * value/property as opposed to a single-bit feature. Again, pack the info
> > diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c b/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
> > new file mode 100644
> > index 000000000000..13c1b03294a4
> > --- /dev/null
> > +++ b/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
> > @@ -0,0 +1,94 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Test Hyper-V extended hypercall, HV_EXT_CALL_QUERY_CAPABILITIES (0x8001),
> > + * exit to userspace and receive result in guest.
> > + *
> > + * Negative tests are present in hyperv_features.c
> > + *
> > + * Copyright 2022 Google LLC
> > + * Author: Vipin Sharma <vipinsh@google.com>
> > + */
> > +
> > +#include "kvm_util.h"
> > +#include "processor.h"
> > +#include "hyperv.h"
> > +
> > +/* Any value is fine */
> > +#define EXT_CAPABILITIES 0xbull
> > +
> > +static void guest_code(vm_vaddr_t in_pg_gpa, vm_vaddr_t out_pg_gpa,
> > + vm_vaddr_t out_pg_gva)
> > +{
> > + uint64_t *output_gva;
> > +
> > + wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
> > + wrmsr(HV_X64_MSR_HYPERCALL, in_pg_gpa);
> > +
> > + output_gva = (uint64_t *)out_pg_gva;
> > +
> > + hyperv_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, in_pg_gpa, out_pg_gpa);
> > +
> > + /* TLFS states output will be a uint64_t value */
> > + GUEST_ASSERT_EQ(*output_gva, EXT_CAPABILITIES);
> > +
> > + GUEST_DONE();
> > +}
> > +
> > +int main(void)
> > +{
> > + vm_vaddr_t hcall_out_page;
> > + vm_vaddr_t hcall_in_page;
> > + struct kvm_vcpu *vcpu;
> > + struct kvm_run *run;
> > + struct kvm_vm *vm;
> > + uint64_t *outval;
> > + struct ucall uc;
> > +
> > + /* Verify if extended hypercalls are supported */
> > + if (!kvm_cpuid_has(kvm_get_supported_hv_cpuid(),
> > + X86_FEATURE_HYPERV_EXTENDED_HYPERCALLS)) {
> > + print_skip("Extended calls not supported by the kernel");
> > + exit(KSFT_SKIP);
> > + }
> > +
> > + vm = vm_create_with_one_vcpu(&vcpu, guest_code);
> > + run = vcpu->run;
> > + vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_ENFORCE_CPUID, 1);
>
> Do we need this enforcement assuming we have no plans to add 'negative'
> tests here (hyperv_features does it just fine)? vcpu_set_hv_cpuid()
> enables everything anyway...
>
We do not. I will remove it.
> > + vcpu_set_hv_cpuid(vcpu);
> > +
> > + /* Hypercall input */
> > + hcall_in_page = vm_vaddr_alloc_pages(vm, 1);
> > + memset(addr_gva2hva(vm, hcall_in_page), 0x0, vm->page_size);
> > +
> > + /* Hypercall output */
> > + hcall_out_page = vm_vaddr_alloc_pages(vm, 1);
> > + memset(addr_gva2hva(vm, hcall_out_page), 0x0, vm->page_size);
> > +
> > + vcpu_args_set(vcpu, 3, addr_gva2gpa(vm, hcall_in_page),
> > + addr_gva2gpa(vm, hcall_out_page), hcall_out_page);
> > +
> > + vcpu_run(vcpu);
> > +
> > + ASSERT_EXIT_REASON(vcpu, KVM_EXIT_HYPERV);
> > +
> > + outval = addr_gpa2hva(vm, run->hyperv.u.hcall.params[1]);
> > + *outval = EXT_CAPABILITIES;
> > + run->hyperv.u.hcall.result = HV_STATUS_SUCCESS;
> > +
> > + vcpu_run(vcpu);
> > +
> > + ASSERT_EXIT_REASON(vcpu, KVM_EXIT_IO);
> > +
> > + switch (get_ucall(vcpu, &uc)) {
> > + case UCALL_ABORT:
> > + REPORT_GUEST_ASSERT_2(uc, "arg1 = %ld, arg2 = %ld");
> > + break;
> > + case UCALL_DONE:
> > + break;
> > + default:
> > + TEST_FAIL("Unhandled ucall: %ld", uc.cmd);
> > + }
> > +
> > + kvm_vm_free(vm);
> > + return 0;
> > +}
>
> --
> Vitaly
>
@@ -24,6 +24,7 @@
/x86_64/hyperv_clock
/x86_64/hyperv_cpuid
/x86_64/hyperv_evmcs
+/x86_64/hyperv_extended_hypercalls
/x86_64/hyperv_features
/x86_64/hyperv_ipi
/x86_64/hyperv_svm_test
@@ -87,6 +87,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/fix_hypercall_test
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_clock
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_evmcs
+TEST_GEN_PROGS_x86_64 += x86_64/hyperv_extended_hypercalls
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_features
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_ipi
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_svm_test
@@ -168,6 +168,9 @@ struct kvm_x86_cpu_feature {
#define X86_FEATURE_KVM_HC_MAP_GPA_RANGE KVM_X86_CPU_FEATURE(0x40000001, 0, EAX, 16)
#define X86_FEATURE_KVM_MIGRATION_CONTROL KVM_X86_CPU_FEATURE(0x40000001, 0, EAX, 17)
+/* Hyper-V defined paravirt features */
+#define X86_FEATURE_HYPERV_EXTENDED_HYPERCALLS KVM_X86_CPU_FEATURE(0x40000003, 0, EBX, 20)
+
/*
* Same idea as X86_FEATURE_XXX, but X86_PROPERTY_XXX retrieves a multi-bit
* value/property as opposed to a single-bit feature. Again, pack the info
new file mode 100644
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test Hyper-V extended hypercall, HV_EXT_CALL_QUERY_CAPABILITIES (0x8001),
+ * exit to userspace and receive result in guest.
+ *
+ * Negative tests are present in hyperv_features.c
+ *
+ * Copyright 2022 Google LLC
+ * Author: Vipin Sharma <vipinsh@google.com>
+ */
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "hyperv.h"
+
+/* Any value is fine */
+#define EXT_CAPABILITIES 0xbull
+
+static void guest_code(vm_vaddr_t in_pg_gpa, vm_vaddr_t out_pg_gpa,
+ vm_vaddr_t out_pg_gva)
+{
+ uint64_t *output_gva;
+
+ wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
+ wrmsr(HV_X64_MSR_HYPERCALL, in_pg_gpa);
+
+ output_gva = (uint64_t *)out_pg_gva;
+
+ hyperv_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, in_pg_gpa, out_pg_gpa);
+
+ /* TLFS states output will be a uint64_t value */
+ GUEST_ASSERT_EQ(*output_gva, EXT_CAPABILITIES);
+
+ GUEST_DONE();
+}
+
+int main(void)
+{
+ vm_vaddr_t hcall_out_page;
+ vm_vaddr_t hcall_in_page;
+ struct kvm_vcpu *vcpu;
+ struct kvm_run *run;
+ struct kvm_vm *vm;
+ uint64_t *outval;
+ struct ucall uc;
+
+ /* Verify if extended hypercalls are supported */
+ if (!kvm_cpuid_has(kvm_get_supported_hv_cpuid(),
+ X86_FEATURE_HYPERV_EXTENDED_HYPERCALLS)) {
+ print_skip("Extended calls not supported by the kernel");
+ exit(KSFT_SKIP);
+ }
+
+ vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+ run = vcpu->run;
+ vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_ENFORCE_CPUID, 1);
+ vcpu_set_hv_cpuid(vcpu);
+
+ /* Hypercall input */
+ hcall_in_page = vm_vaddr_alloc_pages(vm, 1);
+ memset(addr_gva2hva(vm, hcall_in_page), 0x0, vm->page_size);
+
+ /* Hypercall output */
+ hcall_out_page = vm_vaddr_alloc_pages(vm, 1);
+ memset(addr_gva2hva(vm, hcall_out_page), 0x0, vm->page_size);
+
+ vcpu_args_set(vcpu, 3, addr_gva2gpa(vm, hcall_in_page),
+ addr_gva2gpa(vm, hcall_out_page), hcall_out_page);
+
+ vcpu_run(vcpu);
+
+ ASSERT_EXIT_REASON(vcpu, KVM_EXIT_HYPERV);
+
+ outval = addr_gpa2hva(vm, run->hyperv.u.hcall.params[1]);
+ *outval = EXT_CAPABILITIES;
+ run->hyperv.u.hcall.result = HV_STATUS_SUCCESS;
+
+ vcpu_run(vcpu);
+
+ ASSERT_EXIT_REASON(vcpu, KVM_EXIT_IO);
+
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_ABORT:
+ REPORT_GUEST_ASSERT_2(uc, "arg1 = %ld, arg2 = %ld");
+ break;
+ case UCALL_DONE:
+ break;
+ default:
+ TEST_FAIL("Unhandled ucall: %ld", uc.cmd);
+ }
+
+ kvm_vm_free(vm);
+ return 0;
+}