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svm: INIT test and test_run on selected vcpu

PATCH Superseded Cathy Avery 2 participants 5 messages Jun 8, 2020 KVM

v1 of 2 Superseded Latest is v2 →

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Cathy Avery

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#0 lore raw

cover svm: INIT test and test_run on selected vcpu

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(-)
Signature · 1 line
2.20.1
author
#1 lore raw

PATCH 1/2 svm: Add ability to execute test via test_run on a vcpu other than vcpu 0

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 <[email protected]>
---
 x86/svm.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 x86/svm.h | 13 +++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
x86/svm.c +48 -1
index 41685bf..9f7ae7e 100644
@@ -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]);
x86/svm.h +13 -0
index 645deb7..d023a32 100644
@@ -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);
Signature · 1 line
2.20.1
maintainer
#2 lore raw

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

Quoted 38 lines · 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 <[email protected]>
---
 x86/svm.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 x86/svm.h | 13 +++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
x86/svm.c +17 -0
index 41685bf..9f7ae7e 100644
@@ -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)
+{

x86/svm.c test_wanted(const char *name, char *filters[], int filter_count) · line 396

Quoted 10 lines
x86/svm.c +10 -0
+    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

author
#3 lore raw

PATCH 2/2 svm: INIT intercept test

In reply to Cathy Avery

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

Signed-off-by Cathy Avery <[email protected]>
---
 x86/svm_tests.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
x86/svm_tests.c +40 -0
index c1abd55..a4dbe91 100644
@@ -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 }
 };
Signature · 1 line
2.20.1
maintainer
#4 lore raw

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

Quoted 4 lines · Cathy Avery

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

Signed-off-by Cathy Avery <[email protected]>

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

Quoted 63 lines
---
 x86/svm_tests.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
x86/svm_tests.c +40 -0
index c1abd55..a4dbe91 100644
@@ -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 }
 };