KVM: selftests: test KVM_GUESTDBG_BLOCKIRQ

Modify debug_regs test to create a pending interrupt
and see that it is blocked when single stepping is done
with KVM_GUESTDBG_BLOCKIRQ

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210811122927.900604-7-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/x86_64/debug_regs.c b/tools/testing/selftests/kvm/x86_64/debug_regs.c
index 6097a82..5f078db 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/debug_regs.c
+++ b/tools/testing/selftests/kvm/x86_64/debug_regs.c
@@ -8,12 +8,15 @@
 #include <string.h>
 #include "kvm_util.h"
 #include "processor.h"
+#include "apic.h"
 
 #define VCPU_ID 0
 
 #define DR6_BD         (1 << 13)
 #define DR7_GD         (1 << 13)
 
+#define IRQ_VECTOR 0xAA
+
 /* For testing data access debug BP */
 uint32_t guest_value;
 
@@ -21,6 +24,11 @@ extern unsigned char sw_bp, hw_bp, write_data, ss_start, bd_start;
 
 static void guest_code(void)
 {
+       /* Create a pending interrupt on current vCPU */
+       x2apic_enable();
+       x2apic_write_reg(APIC_ICR, APIC_DEST_SELF | APIC_INT_ASSERT |
+                        APIC_DM_FIXED | IRQ_VECTOR);
+
        /*
         * Software BP tests.
         *
@@ -38,12 +46,19 @@ static void guest_code(void)
                     "mov %%rax,%0;\n\t write_data:"
                     : "=m" (guest_value) : : "rax");
 
-       /* Single step test, covers 2 basic instructions and 2 emulated */
+       /*
+        * Single step test, covers 2 basic instructions and 2 emulated
+        *
+        * Enable interrupts during the single stepping to see that
+        * pending interrupt we raised is not handled due to KVM_GUESTDBG_BLOCKIRQ
+        */
        asm volatile("ss_start: "
+                    "sti\n\t"
                     "xor %%eax,%%eax\n\t"
                     "cpuid\n\t"
                     "movl $0x1a0,%%ecx\n\t"
                     "rdmsr\n\t"
+                    "cli\n\t"
                     : : : "eax", "ebx", "ecx", "edx");
 
        /* DR6.BD test */
@@ -72,11 +87,13 @@ int main(void)
        uint64_t cmd;
        int i;
        /* Instruction lengths starting at ss_start */
-       int ss_size[4] = {
+       int ss_size[6] = {
+               1,              /* sti*/
                2,              /* xor */
                2,              /* cpuid */
                5,              /* mov */
                2,              /* rdmsr */
+               1,              /* cli */
        };
 
        if (!kvm_check_cap(KVM_CAP_SET_GUEST_DEBUG)) {
@@ -154,7 +171,8 @@ int main(void)
        for (i = 0; i < (sizeof(ss_size) / sizeof(ss_size[0])); i++) {
                target_rip += ss_size[i];
                CLEAR_DEBUG();
-               debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP;
+               debug.control = KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP |
+                               KVM_GUESTDBG_BLOCKIRQ;
                debug.arch.debugreg[7] = 0x00000400;
                APPLY_DEBUG();
                vcpu_run(vm, VCPU_ID);