[PATCH kvm-unit-tests 0/2] svm: INIT test and test_run on selected vcpu

[PATCH kvm-unit-tests 0/2] svm: INIT test and test_run on selected vcpu

[Cathy Avery]

INIT intercept test and the ability to execute test_run
on a selected vcpu.

Cathy Avery (2):
  svm: Add ability to execute test via test_run on a vcpu other than
    vcpu 0
  svm: INIT intercept test

 x86/svm.c       | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 x86/svm.h       | 13 +++++++++++++
 x86/svm_tests.c | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 101 insertions(+), 1 deletion(-)

-- 
2.20.1

[PATCH kvm-unit-tests 1/2] svm: Add ability to execute test via test_run on a vcpu other than vcpu 0

[Cathy Avery]

When running tests that can result in a vcpu being left in an
indeterminate state it is useful to be able to run the test on
a vcpu other than 0. This patch allows test_run to be executed
on any vcpu indicated by the on_vcpu member of the svm_test struct.
The initialized state of the vcpu0 registers used to populate the
vmcb is carried forward to the other vcpus.

Signed-off-by: Cathy Avery <cavery@redhat.com>
---
 x86/svm.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 x86/svm.h | 13 +++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/x86/svm.c b/x86/svm.c
index 41685bf..9f7ae7e 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -367,6 +367,45 @@ test_wanted(const char *name, char *filters[], int filter_count)
         }
 }
 
+static void set_additional_vpcu_regs(struct extra_vcpu_info *info)
+{
+    wrmsr(MSR_VM_HSAVE_PA, info->hsave);
+    wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_SVME);
+    wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NX);
+    write_cr3(info->cr3);
+    write_cr4(info->cr4);
+    write_cr0(info->cr0);
+    write_dr6(info->dr6);
+    write_dr7(info->dr7);
+    write_cr2(info->cr2);
+    wrmsr(MSR_IA32_CR_PAT, info->g_pat);
+    wrmsr(MSR_IA32_DEBUGCTLMSR, info->dbgctl);
+}
+
+static void get_additional_vcpu_regs(struct extra_vcpu_info *info)
+{
+    info->hsave = rdmsr(MSR_VM_HSAVE_PA);
+    info->cr3 = read_cr3();
+    info->cr4 = read_cr4();
+    info->cr0 = read_cr0();
+    info->dr7 = read_dr7();
+    info->dr6 = read_dr6();
+    info->cr2 = read_cr2();
+    info->g_pat = rdmsr(MSR_IA32_CR_PAT);
+    info->dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
+}
+
+static void init_additional_vcpu_regs(void)
+{
+    int i;
+    struct extra_vcpu_info info;
+
+    get_additional_vcpu_regs(&info);
+
+    for (i = 1; i < cpu_count(); i++)
+        on_cpu(i, (void *)set_additional_vpcu_regs, &info);
+}
+
 int main(int ac, char **av)
 {
 	int i = 0;
@@ -384,6 +423,8 @@ int main(int ac, char **av)
 
 	setup_svm();
 
+        init_additional_vcpu_regs();
+
 	vmcb = alloc_page();
 
 	for (; svm_tests[i].name != NULL; i++) {
@@ -392,7 +433,13 @@ int main(int ac, char **av)
 		if (svm_tests[i].supported && !svm_tests[i].supported())
 			continue;
 		if (svm_tests[i].v2 == NULL) {
-			test_run(&svm_tests[i]);
+			if (svm_tests[i].on_vcpu) {
+				if (cpu_count() <= svm_tests[i].on_vcpu)
+					continue;
+				on_cpu(svm_tests[i].on_vcpu, (void *)test_run, &svm_tests[i]);
+			}
+			else
+				test_run(&svm_tests[i]);
 		} else {
 			vmcb_ident(vmcb);
 			v2_test = &(svm_tests[i]);
diff --git a/x86/svm.h b/x86/svm.h
index 645deb7..d023a32 100644
--- a/x86/svm.h
+++ b/x86/svm.h
@@ -338,6 +338,7 @@ struct svm_test {
 	ulong scratch;
 	/* Alternative test interface. */
 	void (*v2)(void);
+	int on_vcpu;
 };
 
 struct regs {
@@ -360,6 +361,18 @@ struct regs {
 	u64 rflags;
 };
 
+struct extra_vcpu_info {
+	u64 hsave;
+	u64 cr3;
+	u64 cr4;
+	u64 cr0;
+	u64 dr7;
+	u64 dr6;
+	u64 cr2;
+	u64 g_pat;
+	u64 dbgctl;
+};
+
 typedef void (*test_guest_func)(struct svm_test *);
 
 u64 *npt_get_pte(u64 address);
-- 
2.20.1

[PATCH kvm-unit-tests 2/2] svm: INIT intercept test

[Cathy Avery]

INIT vcpu 2 and intercept the INIT. This test
will leave the vcpu in an unusable state.

Signed-off-by: Cathy Avery <cavery@redhat.com>
---
 x86/svm_tests.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index c1abd55..a4dbe91 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -1789,6 +1789,43 @@ static bool virq_inject_check(struct svm_test *test)
     return get_test_stage(test) == 5;
 }
 
+static volatile bool init_intercept;
+
+static void init_signal_intercept_prepare(struct svm_test *test)
+{
+
+    vmcb_ident(vmcb);
+    vmcb->control.intercept |= (1ULL << INTERCEPT_INIT);
+    init_intercept = false;
+}
+
+static void init_signal_test(struct svm_test *test)
+{
+    apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_INIT | APIC_INT_ASSERT, 0);
+}
+
+static bool init_signal_finished(struct svm_test *test)
+{
+    vmcb->save.rip += 3;
+
+    if (vmcb->control.exit_code != SVM_EXIT_INIT) {
+        report(false, "VMEXIT not due to init intercept. Exit reason 0x%x",
+               vmcb->control.exit_code);
+        return true;
+        }
+
+    init_intercept = true;
+
+    report(true, "INIT to vcpu intercepted");
+
+    return true;
+}
+
+static bool init_signal_check(struct svm_test *test)
+{
+    return init_intercept;
+}
+
 #define TEST(name) { #name, .v2 = name }
 
 /*
@@ -1950,6 +1987,9 @@ struct svm_test svm_tests[] = {
     { "virq_inject", default_supported, virq_inject_prepare,
       default_prepare_gif_clear, virq_inject_test,
       virq_inject_finished, virq_inject_check },
+    { "svm_init_signal_intercept_test", default_supported, init_signal_intercept_prepare,
+      default_prepare_gif_clear, init_signal_test,
+      init_signal_finished, init_signal_check, .on_vcpu = 2 },
     TEST(svm_guest_state_test),
     { NULL, NULL, NULL, NULL, NULL, NULL, NULL }
 };
-- 
2.20.1

Re: [PATCH kvm-unit-tests 1/2] svm: Add ability to execute test via test_run on a vcpu other than vcpu 0

[Paolo Bonzini]

On 08/06/20 14:27, Cathy Avery wrote:
> When running tests that can result in a vcpu being left in an
> indeterminate state it is useful to be able to run the test on
> a vcpu other than 0. This patch allows test_run to be executed
> on any vcpu indicated by the on_vcpu member of the svm_test struct.
> The initialized state of the vcpu0 registers used to populate the
> vmcb is carried forward to the other vcpus.
> 
> Signed-off-by: Cathy Avery <cavery@redhat.com>
> ---
>  x86/svm.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  x86/svm.h | 13 +++++++++++++
>  2 files changed, 61 insertions(+), 1 deletion(-)
> 
> diff --git a/x86/svm.c b/x86/svm.c
> index 41685bf..9f7ae7e 100644
> --- a/x86/svm.c
> +++ b/x86/svm.c
> @@ -367,6 +367,45 @@ test_wanted(const char *name, char *filters[], int filter_count)
>          }
>  }
>  
> +static void set_additional_vpcu_regs(struct extra_vcpu_info *info)
> +{
> +    wrmsr(MSR_VM_HSAVE_PA, info->hsave);
> +    wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_SVME);
> +    wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NX);
> +    write_cr3(info->cr3);
> +    write_cr4(info->cr4);
> +    write_cr0(info->cr0);
> +    write_dr6(info->dr6);
> +    write_dr7(info->dr7);
> +    write_cr2(info->cr2);
> +    wrmsr(MSR_IA32_CR_PAT, info->g_pat);
> +    wrmsr(MSR_IA32_DEBUGCTLMSR, info->dbgctl);
> +}
> +
> +static void get_additional_vcpu_regs(struct extra_vcpu_info *info)
> +{
> +    info->hsave = rdmsr(MSR_VM_HSAVE_PA);
> +    info->cr3 = read_cr3();
> +    info->cr4 = read_cr4();
> +    info->cr0 = read_cr0();
> +    info->dr7 = read_dr7();
> +    info->dr6 = read_dr6();
> +    info->cr2 = read_cr2();
> +    info->g_pat = rdmsr(MSR_IA32_CR_PAT);
> +    info->dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
> +}

Some tweaks are needed here:

- DR6/DR7/CR2/DEBUGCTL should not be needed, are they?  Same for PAT
since it's not modified by the tests and defaults to the "right" value
(0x0007040600070406ULL) rather than zero.

- HSAVE should be set to a different page for each vCPU

- The on_cpu to set EFER should be in setup_svm, rather than a separate
function

- The on_cpu to set cr0/cr3/cr4 should be in setup_vm.

Paolo

Re: [PATCH kvm-unit-tests 2/2] svm: INIT intercept test

[Paolo Bonzini]

On 08/06/20 14:28, Cathy Avery wrote:
> INIT vcpu 2 and intercept the INIT. This test
> will leave the vcpu in an unusable state.
> 
> Signed-off-by: Cathy Avery <cavery@redhat.com>

It should be possible to reinitialize the vCPU using a SIPI interrupt, like

	old = cpu_online_count--;
	apic_icr_write(APIC_DEST_PHYSICAL | APIC_DEST_SIPI,
		       id_map[cpu]);
	while (cpu_online_count != old)
		cpu_relax();

You can test this by using vCPU 1 to run this test.

Paolo

> ---
>  x86/svm_tests.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/x86/svm_tests.c b/x86/svm_tests.c
> index c1abd55..a4dbe91 100644
> --- a/x86/svm_tests.c
> +++ b/x86/svm_tests.c
> @@ -1789,6 +1789,43 @@ static bool virq_inject_check(struct svm_test *test)
>      return get_test_stage(test) == 5;
>  }
>  
> +static volatile bool init_intercept;
> +
> +static void init_signal_intercept_prepare(struct svm_test *test)
> +{
> +
> +    vmcb_ident(vmcb);
> +    vmcb->control.intercept |= (1ULL << INTERCEPT_INIT);
> +    init_intercept = false;
> +}
> +
> +static void init_signal_test(struct svm_test *test)
> +{
> +    apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_INIT | APIC_INT_ASSERT, 0);
> +}
> +
> +static bool init_signal_finished(struct svm_test *test)
> +{
> +    vmcb->save.rip += 3;
> +
> +    if (vmcb->control.exit_code != SVM_EXIT_INIT) {
> +        report(false, "VMEXIT not due to init intercept. Exit reason 0x%x",
> +               vmcb->control.exit_code);
> +        return true;
> +        }
> +
> +    init_intercept = true;
> +
> +    report(true, "INIT to vcpu intercepted");
> +
> +    return true;
> +}
> +
> +static bool init_signal_check(struct svm_test *test)
> +{
> +    return init_intercept;
> +}
> +
>  #define TEST(name) { #name, .v2 = name }
>  
>  /*
> @@ -1950,6 +1987,9 @@ struct svm_test svm_tests[] = {
>      { "virq_inject", default_supported, virq_inject_prepare,
>        default_prepare_gif_clear, virq_inject_test,
>        virq_inject_finished, virq_inject_check },
> +    { "svm_init_signal_intercept_test", default_supported, init_signal_intercept_prepare,
> +      default_prepare_gif_clear, init_signal_test,
> +      init_signal_finished, init_signal_check, .on_vcpu = 2 },
>      TEST(svm_guest_state_test),
>      { NULL, NULL, NULL, NULL, NULL, NULL, NULL }
>  };
>