KVM Archive on lore.kernel.org
 help / color / Atom feed
* [PATCH kvm-unit-tests v2] svm: Verify the effect of V_INTR_MASKING on INTR interrupts
@ 2019-12-03 16:25 Cathy Avery
  2019-12-10 17:00 ` Paolo Bonzini
  0 siblings, 1 reply; 2+ messages in thread
From: Cathy Avery @ 2019-12-03 16:25 UTC (permalink / raw)
  To: kvm, pbonzini

The test confirms the influence of the V_INTR_MASKING bit
on RFLAGS.IF. The expectation is while running a guest
with V_INTR_MASKING cleared to zero:

- EFLAGS.IF controls both virtual and physical interrupts.

While running a guest with V_INTR_MASKING set to 1:

- The host EFLAGS.IF at the time of the VMRUN is saved and
  controls physical interrupts while the guest is running.

- The guest value of EFLAGS.IF controls virtual interrupts only.

As discussed previously, this patch also modifies the vmrun
loop ( test_run ) to allow running with HIF=0

Signed-off-by: Cathy Avery <cavery@redhat.com>
---

v2: Added suggested changes to set_host_if etc.
---
 x86/svm.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 103 insertions(+), 2 deletions(-)

diff --git a/x86/svm.c b/x86/svm.c
index 0360d8d..626179c 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -44,6 +44,8 @@ u64 runs;
 u8 *io_bitmap;
 u8 io_bitmap_area[16384];
 
+u8 set_host_if;
+
 #define MSR_BITMAP_SIZE 8192
 
 u8 *msr_bitmap;
@@ -258,6 +260,7 @@ static void test_run(struct test *test, struct vmcb *vmcb)
 
     irq_disable();
     test->vmcb = vmcb;
+    set_host_if = 1;
     test->prepare(test);
     vmcb->save.rip = (ulong)test_thunk;
     vmcb->save.rsp = (ulong)(guest_stack + ARRAY_SIZE(guest_stack));
@@ -266,21 +269,24 @@ static void test_run(struct test *test, struct vmcb *vmcb)
         tsc_start = rdtsc();
         asm volatile (
             "clgi \n\t"
+            "cmpb $0, set_host_if\n\t"
+            "jz 1f\n\t"
+            "sti \n\t"
+            "1: \n\t"
             "vmload \n\t"
             "mov regs+0x80, %%r15\n\t"  // rflags
             "mov %%r15, 0x170(%0)\n\t"
             "mov regs, %%r15\n\t"       // rax
             "mov %%r15, 0x1f8(%0)\n\t"
             LOAD_GPR_C
-            "sti \n\t"		// only used if V_INTR_MASKING=1
             "vmrun \n\t"
-            "cli \n\t"
             SAVE_GPR_C
             "mov 0x170(%0), %%r15\n\t"  // rflags
             "mov %%r15, regs+0x80\n\t"
             "mov 0x1f8(%0), %%r15\n\t"  // rax
             "mov %%r15, regs\n\t"
             "vmsave \n\t"
+            "cli \n\t"
             "stgi"
             : : "a"(vmcb_phys)
             : "rbx", "rcx", "rdx", "rsi",
@@ -1386,6 +1392,98 @@ static bool pending_event_check(struct test *test)
     return get_test_stage(test) == 2;
 }
 
+static void pending_event_prepare_vmask(struct test *test)
+{
+    default_prepare(test);
+
+    pending_event_ipi_fired = false;
+
+    set_host_if = 0;
+
+    handle_irq(0xf1, pending_event_ipi_isr);
+
+    apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL |
+              APIC_DM_FIXED | 0xf1, 0);
+
+    set_test_stage(test, 0);
+}
+
+static void pending_event_test_vmask(struct test *test)
+{
+    if (pending_event_ipi_fired == true) {
+        set_test_stage(test, -1);
+        report("Interrupt preceeded guest", false);
+        vmmcall();
+    }
+
+    irq_enable();
+    asm volatile ("nop");
+    irq_disable();
+
+    if (pending_event_ipi_fired != true) {
+        set_test_stage(test, -1);
+        report("Interrupt not triggered by guest", false);
+    }
+
+    vmmcall();
+
+    irq_enable();
+    asm volatile ("nop");
+    irq_disable();
+}
+
+static bool pending_event_finished_vmask(struct test *test)
+{
+    if ( test->vmcb->control.exit_code != SVM_EXIT_VMMCALL) {
+        report("VM_EXIT return to host is not EXIT_VMMCALL exit reason 0x%x", false,
+                test->vmcb->control.exit_code);
+        return true;
+    }
+
+    switch (get_test_stage(test)) {
+    case 0:
+        test->vmcb->save.rip += 3;
+
+        pending_event_ipi_fired = false;
+
+        test->vmcb->control.int_ctl |= V_INTR_MASKING_MASK;
+
+        apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL |
+              APIC_DM_FIXED | 0xf1, 0);
+
+        break;
+
+    case 1:
+        if (pending_event_ipi_fired == true) {
+            report("Interrupt triggered by guest", false);
+            return true;
+        }
+
+        irq_enable();
+        asm volatile ("nop");
+        irq_disable();
+
+        if (pending_event_ipi_fired != true) {
+            report("Interrupt not triggered by host", false);
+            return true;
+        }
+
+        break;
+
+    default:
+        return true;
+    }
+
+    inc_test_stage(test);
+
+    return get_test_stage(test) == 2;
+}
+
+static bool pending_event_check_vmask(struct test *test)
+{
+    return get_test_stage(test) == 2;
+}
+
 static struct test tests[] = {
     { "null", default_supported, default_prepare, null_test,
       default_finished, null_check },
@@ -1438,6 +1536,9 @@ static struct test tests[] = {
       lat_svm_insn_finished, lat_svm_insn_check },
     { "pending_event", default_supported, pending_event_prepare,
       pending_event_test, pending_event_finished, pending_event_check },
+    { "pending_event_vmask", default_supported, pending_event_prepare_vmask,
+      pending_event_test_vmask, pending_event_finished_vmask,
+      pending_event_check_vmask },
 };
 
 int main(int ac, char **av)
-- 
2.20.1


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH kvm-unit-tests v2] svm: Verify the effect of V_INTR_MASKING on INTR interrupts
  2019-12-03 16:25 [PATCH kvm-unit-tests v2] svm: Verify the effect of V_INTR_MASKING on INTR interrupts Cathy Avery
@ 2019-12-10 17:00 ` Paolo Bonzini
  0 siblings, 0 replies; 2+ messages in thread
From: Paolo Bonzini @ 2019-12-10 17:00 UTC (permalink / raw)
  To: Cathy Avery, kvm

On 03/12/19 17:25, Cathy Avery wrote:
> The test confirms the influence of the V_INTR_MASKING bit
> on RFLAGS.IF. The expectation is while running a guest
> with V_INTR_MASKING cleared to zero:
> 
> - EFLAGS.IF controls both virtual and physical interrupts.
> 
> While running a guest with V_INTR_MASKING set to 1:
> 
> - The host EFLAGS.IF at the time of the VMRUN is saved and
>   controls physical interrupts while the guest is running.
> 
> - The guest value of EFLAGS.IF controls virtual interrupts only.
> 
> As discussed previously, this patch also modifies the vmrun
> loop ( test_run ) to allow running with HIF=0
> 
> Signed-off-by: Cathy Avery <cavery@redhat.com>
> ---
> 
> v2: Added suggested changes to set_host_if etc.
> ---
>  x86/svm.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 103 insertions(+), 2 deletions(-)
> 
> diff --git a/x86/svm.c b/x86/svm.c
> index 0360d8d..626179c 100644
> --- a/x86/svm.c
> +++ b/x86/svm.c
> @@ -44,6 +44,8 @@ u64 runs;
>  u8 *io_bitmap;
>  u8 io_bitmap_area[16384];
>  
> +u8 set_host_if;
> +
>  #define MSR_BITMAP_SIZE 8192
>  
>  u8 *msr_bitmap;
> @@ -258,6 +260,7 @@ static void test_run(struct test *test, struct vmcb *vmcb)
>  
>      irq_disable();
>      test->vmcb = vmcb;
> +    set_host_if = 1;
>      test->prepare(test);
>      vmcb->save.rip = (ulong)test_thunk;
>      vmcb->save.rsp = (ulong)(guest_stack + ARRAY_SIZE(guest_stack));
> @@ -266,21 +269,24 @@ static void test_run(struct test *test, struct vmcb *vmcb)
>          tsc_start = rdtsc();
>          asm volatile (
>              "clgi \n\t"
> +            "cmpb $0, set_host_if\n\t"
> +            "jz 1f\n\t"
> +            "sti \n\t"
> +            "1: \n\t"
>              "vmload \n\t"
>              "mov regs+0x80, %%r15\n\t"  // rflags
>              "mov %%r15, 0x170(%0)\n\t"
>              "mov regs, %%r15\n\t"       // rax
>              "mov %%r15, 0x1f8(%0)\n\t"
>              LOAD_GPR_C
> -            "sti \n\t"		// only used if V_INTR_MASKING=1
>              "vmrun \n\t"
> -            "cli \n\t"
>              SAVE_GPR_C
>              "mov 0x170(%0), %%r15\n\t"  // rflags
>              "mov %%r15, regs+0x80\n\t"
>              "mov 0x1f8(%0), %%r15\n\t"  // rax
>              "mov %%r15, regs\n\t"
>              "vmsave \n\t"
> +            "cli \n\t"
>              "stgi"
>              : : "a"(vmcb_phys)
>              : "rbx", "rcx", "rdx", "rsi",
> @@ -1386,6 +1392,98 @@ static bool pending_event_check(struct test *test)
>      return get_test_stage(test) == 2;
>  }
>  
> +static void pending_event_prepare_vmask(struct test *test)
> +{
> +    default_prepare(test);
> +
> +    pending_event_ipi_fired = false;
> +
> +    set_host_if = 0;
> +
> +    handle_irq(0xf1, pending_event_ipi_isr);
> +
> +    apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL |
> +              APIC_DM_FIXED | 0xf1, 0);
> +
> +    set_test_stage(test, 0);
> +}
> +
> +static void pending_event_test_vmask(struct test *test)
> +{
> +    if (pending_event_ipi_fired == true) {
> +        set_test_stage(test, -1);
> +        report("Interrupt preceeded guest", false);
> +        vmmcall();
> +    }
> +
> +    irq_enable();
> +    asm volatile ("nop");
> +    irq_disable();
> +
> +    if (pending_event_ipi_fired != true) {
> +        set_test_stage(test, -1);
> +        report("Interrupt not triggered by guest", false);
> +    }
> +
> +    vmmcall();
> +
> +    irq_enable();
> +    asm volatile ("nop");
> +    irq_disable();
> +}
> +
> +static bool pending_event_finished_vmask(struct test *test)
> +{
> +    if ( test->vmcb->control.exit_code != SVM_EXIT_VMMCALL) {
> +        report("VM_EXIT return to host is not EXIT_VMMCALL exit reason 0x%x", false,
> +                test->vmcb->control.exit_code);
> +        return true;
> +    }
> +
> +    switch (get_test_stage(test)) {
> +    case 0:
> +        test->vmcb->save.rip += 3;
> +
> +        pending_event_ipi_fired = false;
> +
> +        test->vmcb->control.int_ctl |= V_INTR_MASKING_MASK;
> +
> +        apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL |
> +              APIC_DM_FIXED | 0xf1, 0);
> +
> +        break;
> +
> +    case 1:
> +        if (pending_event_ipi_fired == true) {
> +            report("Interrupt triggered by guest", false);
> +            return true;
> +        }
> +
> +        irq_enable();
> +        asm volatile ("nop");
> +        irq_disable();
> +
> +        if (pending_event_ipi_fired != true) {
> +            report("Interrupt not triggered by host", false);
> +            return true;
> +        }
> +
> +        break;
> +
> +    default:
> +        return true;
> +    }
> +
> +    inc_test_stage(test);
> +
> +    return get_test_stage(test) == 2;
> +}
> +
> +static bool pending_event_check_vmask(struct test *test)
> +{
> +    return get_test_stage(test) == 2;
> +}
> +
>  static struct test tests[] = {
>      { "null", default_supported, default_prepare, null_test,
>        default_finished, null_check },
> @@ -1438,6 +1536,9 @@ static struct test tests[] = {
>        lat_svm_insn_finished, lat_svm_insn_check },
>      { "pending_event", default_supported, pending_event_prepare,
>        pending_event_test, pending_event_finished, pending_event_check },
> +    { "pending_event_vmask", default_supported, pending_event_prepare_vmask,
> +      pending_event_test_vmask, pending_event_finished_vmask,
> +      pending_event_check_vmask },
>  };
>  
>  int main(int ac, char **av)
> 

Applied, thanks.

Paolo


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, back to index

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-12-03 16:25 [PATCH kvm-unit-tests v2] svm: Verify the effect of V_INTR_MASKING on INTR interrupts Cathy Avery
2019-12-10 17:00 ` Paolo Bonzini

KVM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvm/0 kvm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvm kvm/ https://lore.kernel.org/kvm \
		kvm@vger.kernel.org
	public-inbox-index kvm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.kvm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git