(an interrupt, SMI, NMI), but lets L2 control either EFLAG.IF or GIF
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
x86/svm.h | 11 +++
x86/svm_tests.c | 194 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 205 insertions(+)
diff --git a/x86/svm.h b/x86/svm.h
index 58b9410..df1b1ac 100644
--- a/x86/svm.h
+++ b/x86/svm.h
@@ -426,6 +426,17 @@ void test_set_guest(test_guest_func func);
extern struct vmcb *vmcb;
extern struct svm_test svm_tests[];
+static inline void stgi(void)
+{
+ asm volatile ("stgi");
+}
+
+static inline void clgi(void)
+{
+ asm volatile ("clgi");
+}
+
+
#define SAVE_GPR_C \
"xchg %%rbx, regs+0x8\n\t" \
diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index b2ba283..ef8b5ee 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -3312,6 +3312,195 @@ static void svm_lbrv_nested_test2(void)
check_lbr(&host_branch4_from, &host_branch4_to);
}
+
+// test that a nested guest which does enable INTR interception
+// but doesn't enable virtual interrupt masking works
+
+static volatile int dummy_isr_recevied;
+static void dummy_isr(isr_regs_t *regs)
+{
+ dummy_isr_recevied++;
+ eoi();
+}
+
+
+static volatile int nmi_recevied;
+static void dummy_nmi_handler(struct ex_regs *regs)
+{
+ nmi_recevied++;
+}
+
+
+static void svm_intr_intercept_mix_run_guest(volatile int *counter, int expected_vmexit)
+{
+ if (counter)
+ *counter = 0;
+
+ sti(); // host IF value should not matter
+ clgi(); // vmrun will set back GI to 1
+
+ svm_vmrun();
+
+ if (counter)
+ report(!*counter, "No interrupt expected");
+
+ stgi();
+
+ if (counter)
+ report(*counter == 1, "Interrupt is expected");
+
+ report (vmcb->control.exit_code == expected_vmexit, "Test expected VM exit");
+ report(vmcb->save.rflags & X86_EFLAGS_IF, "Guest should have EFLAGS.IF set now");
+ cli();
+}
+
+
+// subtest: test that enabling EFLAGS.IF is enought to trigger an interrupt
+static void svm_intr_intercept_mix_if_guest(struct svm_test *test)
+{
+ asm volatile("nop;nop;nop;nop");
+ report(!dummy_isr_recevied, "No interrupt expected");
+ sti();
+ asm volatile("nop");
+ report(0, "must not reach here");
+}
+
+static void svm_intr_intercept_mix_if(void)
+{
+ // make a physical interrupt to be pending
+ handle_irq(0x55, dummy_isr);
+
+ vmcb->control.intercept |= (1 << INTERCEPT_INTR);
+ vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;
+ vmcb->save.rflags &= ~X86_EFLAGS_IF;
+
+ test_set_guest(svm_intr_intercept_mix_if_guest);
+ apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_FIXED | 0x55, 0);
+ svm_intr_intercept_mix_run_guest(&dummy_isr_recevied, SVM_EXIT_INTR);
+}
+
+
+// subtest: test that a clever guest can trigger an interrupt by setting GIF
+// if GIF is not intercepted
+static void svm_intr_intercept_mix_gif_guest(struct svm_test *test)
+{
+
+ asm volatile("nop;nop;nop;nop");
+ report(!dummy_isr_recevied, "No interrupt expected");
+
+ // clear GIF and enable IF
+ // that should still not cause VM exit
+ clgi();
+ sti();
+ asm volatile("nop");
+ report(!dummy_isr_recevied, "No interrupt expected");
+
+ stgi();
+ asm volatile("nop");
+ report(0, "must not reach here");
+}
+
+static void svm_intr_intercept_mix_gif(void)
+{
+ handle_irq(0x55, dummy_isr);
+
+ vmcb->control.intercept |= (1 << INTERCEPT_INTR);
+ vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;
+ vmcb->save.rflags &= ~X86_EFLAGS_IF;
+
+ test_set_guest(svm_intr_intercept_mix_gif_guest);
+ apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_FIXED | 0x55, 0);
+ svm_intr_intercept_mix_run_guest(&dummy_isr_recevied, SVM_EXIT_INTR);
+}
+
+
+
+// subtest: test that a clever guest can trigger an interrupt by setting GIF
+// if GIF is not intercepted and interrupt comes after guest
+// started running
+static void svm_intr_intercept_mix_gif_guest2(struct svm_test *test)
+{
+ asm volatile("nop;nop;nop;nop");
+ report(!dummy_isr_recevied, "No interrupt expected");
+
+ clgi();
+ apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_FIXED | 0x55, 0);
+ report(!dummy_isr_recevied, "No interrupt expected");
+
+ stgi();
+ asm volatile("nop");
+ report(0, "must not reach here");
+}
+
+static void svm_intr_intercept_mix_gif2(void)
+{
+ handle_irq(0x55, dummy_isr);
+
+ vmcb->control.intercept |= (1 << INTERCEPT_INTR);
+ vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;
+ vmcb->save.rflags |= X86_EFLAGS_IF;
+
+ test_set_guest(svm_intr_intercept_mix_gif_guest2);
+ svm_intr_intercept_mix_run_guest(&dummy_isr_recevied, SVM_EXIT_INTR);
+}
+
+
+// subtest: test that pending NMI will be handled when guest enables GIF
+static void svm_intr_intercept_mix_nmi_guest(struct svm_test *test)
+{
+ asm volatile("nop;nop;nop;nop");
+ report(!nmi_recevied, "No NMI expected");
+ cli(); // should have no effect
+
+ clgi();
+ asm volatile("nop");
+ apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_NMI, 0);
+ sti(); // should have no effect
+ asm volatile("nop");
+ report(!nmi_recevied, "No NMI expected");
+
+ stgi();
+ asm volatile("nop");
+ report(0, "must not reach here");
+}
+
+static void svm_intr_intercept_mix_nmi(void)
+{
+ handle_exception(2, dummy_nmi_handler);
+
+ vmcb->control.intercept |= (1 << INTERCEPT_NMI);
+ vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;
+ vmcb->save.rflags |= X86_EFLAGS_IF;
+
+ test_set_guest(svm_intr_intercept_mix_nmi_guest);
+ svm_intr_intercept_mix_run_guest(&nmi_recevied, SVM_EXIT_NMI);
+}
+
+// test that pending SMI will be handled when guest enables GIF
+// TODO: can't really count #SMIs so just test that guest doesn't hang
+// and VMexits on SMI
+static void svm_intr_intercept_mix_smi_guest(struct svm_test *test)
+{
+ asm volatile("nop;nop;nop;nop");
+
+ clgi();
+ asm volatile("nop");
+ apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_SMI, 0);
+ sti(); // should have no effect
+ asm volatile("nop");
+ stgi();
+ asm volatile("nop");
+ report(0, "must not reach here");
+}
+
+static void svm_intr_intercept_mix_smi(void)
+{
+ vmcb->control.intercept |= (1 << INTERCEPT_SMI);
+ vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;
+ test_set_guest(svm_intr_intercept_mix_smi_guest);
+ svm_intr_intercept_mix_run_guest(NULL, SVM_EXIT_SMI);
+}
+
struct svm_test svm_tests[] = {
{ "null", default_supported, default_prepare,
default_prepare_gif_clear, null_test,
@@ -3439,5 +3628,10 @@ struct svm_test svm_tests[] = {
TEST(svm_lbrv_test2),
TEST(svm_lbrv_nested_test1),
TEST(svm_lbrv_nested_test2),
+ TEST(svm_intr_intercept_mix_if),
+ TEST(svm_intr_intercept_mix_gif),
+ TEST(svm_intr_intercept_mix_gif2),
+ TEST(svm_intr_intercept_mix_nmi),
+ TEST(svm_intr_intercept_mix_smi),
{ NULL, NULL, NULL, NULL, NULL, NULL, NULL }
};
--
2.26.3
