Extend SAVIC test to verify APIC MSR accesses in SAVIC enabled
mode. Verify the behavior of reads and writes using rdmsr/wrmsr
for various APIC registers. In addition, test whether wrmsr
based writes are propagated to guest backing page.
Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx>
---
.../testing/selftests/kvm/include/x86/apic.h | 1 +
.../testing/selftests/kvm/include/x86/savic.h | 3 +
tools/testing/selftests/kvm/lib/x86/savic.c | 7 +-
tools/testing/selftests/kvm/x86/savic_test.c | 192 +++++++++++++++++-
4 files changed, 198 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/apic.h b/tools/testing/selftests/kvm/include/x86/apic.h
index aa3a5d54c404..af555638086f 100644
--- a/tools/testing/selftests/kvm/include/x86/apic.h
+++ b/tools/testing/selftests/kvm/include/x86/apic.h
@@ -33,6 +33,7 @@
#define APIC_SPIV 0xF0
#define APIC_SPIV_FOCUS_DISABLED (1 << 9)
#define APIC_SPIV_APIC_ENABLED (1 << 8)
+#define APIC_ISR 0x100
#define APIC_TMR 0x180
#define APIC_IRR 0x200
#define APIC_ICR 0x300
diff --git a/tools/testing/selftests/kvm/include/x86/savic.h b/tools/testing/selftests/kvm/include/x86/savic.h
index cb432eb527b3..33f19f5e39b3 100644
--- a/tools/testing/selftests/kvm/include/x86/savic.h
+++ b/tools/testing/selftests/kvm/include/x86/savic.h
@@ -6,6 +6,9 @@
#ifndef SELFTEST_KVM_SAVIC_H
#define SELFTEST_KVM_SAVIC_H
+#define APIC_REG_OFF(VEC) (VEC / 32 * 16)
+#define APIC_VEC_POS(VEC) (VEC % 32)
+
struct guest_apic_page;
void guest_apic_pages_init(struct kvm_vm *vm);
diff --git a/tools/testing/selftests/kvm/lib/x86/savic.c b/tools/testing/selftests/kvm/lib/x86/savic.c
index d4c9fcf835ad..c637e486b6e8 100644
--- a/tools/testing/selftests/kvm/lib/x86/savic.c
+++ b/tools/testing/selftests/kvm/lib/x86/savic.c
@@ -9,6 +9,7 @@
#include "kvm_util.h"
#include "sev.h"
#include "ex_regs.h"
+#include "savic.h"
struct apic_page {
u8 apic_regs[PAGE_SIZE];
@@ -45,9 +46,6 @@ enum lapic_lvt_entry {
#define SVM_EXIT_AVIC_UNACCELERATED_ACCESS 0x402
#define SVM_EXIT_AVIC_INCOMPLETE_IPI 0x401
-#define REG_OFF(VEC) (VEC / 32 * 16)
-#define VEC_POS(VEC) (VEC % 32)
-
#define SAVIC_NMI_REQ_OFFSET 0x278
/*
@@ -363,7 +361,8 @@ static void send_ipi(int cpu, int vector, bool nmi)
if (nmi)
savic_write_reg(apic_page, SAVIC_NMI_REQ_OFFSET, 1);
else
- savic_write_reg(apic_page, APIC_IRR + REG_OFF(vector), BIT(VEC_POS(vector)));
+ savic_write_reg(apic_page, APIC_IRR + APIC_REG_OFF(vector),
+ BIT(APIC_VEC_POS(vector)));
}
static bool is_cpu_present(int cpu)
diff --git a/tools/testing/selftests/kvm/x86/savic_test.c b/tools/testing/selftests/kvm/x86/savic_test.c
index ca1d7352bc3e..8cba7a81bce2 100644
--- a/tools/testing/selftests/kvm/x86/savic_test.c
+++ b/tools/testing/selftests/kvm/x86/savic_test.c
@@ -29,6 +29,7 @@ enum savic_test_state {
SAVIC_TEST_STATE(X2APIC_ENABLE),
/* APIC regs state on Secure AVIC enablement */
SAVIC_TEST_STATE(SAVIC_EN),
+ SAVIC_TEST_STATE(SAVIC_APIC_MSR_ACCESSES),
};
/* APIC reg values written by host. */
@@ -288,6 +289,193 @@ static void guest_savic_enabled(int id)
savic_write_apic_regs(apage);
}
+static int savic_wrmsr(uint32_t reg, uint64_t val)
+{
+ switch (reg) {
+ case APIC_LVR:
+ case APIC_LDR:
+ case APIC_ISR:
+ case APIC_TMR:
+ case APIC_IRR:
+ case APIC_TMCCT:
+ x2apic_write_reg_fault(reg, val);
+ return -1;
+ default:
+ x2apic_write_reg(reg, val);
+ break;
+ }
+
+ return 0;
+}
+
+static uint64_t savic_rdmsr(uint32_t reg)
+{
+ uint64_t val;
+ uint32_t msr = APIC_BASE_MSR + (reg >> 4);
+
+ switch (reg) {
+ case APIC_EOI:
+ uint8_t fault = rdmsr_safe(msr, &val);
+
+ __GUEST_ASSERT(fault == GP_VECTOR,
+ "Wanted #GP on RDMSR(%x) = %x, got 0x%x\n",
+ msr, GP_VECTOR, fault);
+ return val;
+ default:
+ return x2apic_read_reg(reg);
+ }
+}
+
+static void guest_verify_host_guest_reg(struct guest_apic_page *apage, uint32_t reg,
+ uint64_t val, char *regname)
+{
+ uint64_t hval, gval, gval2;
+
+ if (savic_wrmsr(reg, val) == -1) {
+ savic_write_reg(apage, reg, val);
+ /*
+ * Write using PV interface if wrmsr fails. Skip for
+ * regs which trigger GP
+ */
+ if (reg != APIC_LVR && reg != APIC_TMR && reg != APIC_IRR)
+ savic_hv_write_reg(reg, val);
+ }
+
+ gval = savic_read_reg(apage, reg);
+ gval2 = savic_rdmsr(reg);
+ hval = savic_hv_read_reg(reg);
+ __GUEST_ASSERT(gval == val, "Unexpected Guest %s 0x%lx, expected val:0x%lx\n",
+ regname, gval, val);
+ __GUEST_ASSERT(gval == gval2, "Unexpected Guest %s backing page value : 0x%lx, msr read val:0x%lx\n",
+ regname, gval, gval2);
+
+ switch (reg) {
+ case APIC_LVR:
+ case APIC_LDR:
+ case APIC_ISR:
+ case APIC_TMICT:
+ case APIC_TDCR:
+ case APIC_LVTT:
+ case APIC_LVTTHMR:
+ case APIC_LVTPC:
+ case APIC_LVT0:
+ case APIC_LVT1:
+ case APIC_LVTERR:
+ __GUEST_ASSERT(hval == gval, "Guest 0x%lx host 0x%lx %s mismatch\n",
+ gval, hval, regname);
+ break;
+ case APIC_TASKPRI:
+ case APIC_SPIV:
+ case APIC_ICR:
+ case APIC_TMR:
+ case APIC_IRR:
+ __GUEST_ASSERT(hval != gval, "Guest 0x%lx host 0x%lx reg: %x %s must not match\n",
+ gval, hval, reg, regname);
+ break;
+ default:
+ break;
+ }
+}
+
+static inline uint32_t x2apic_ldr(uint32_t id)
+{
+ return ((id >> 4) << 16) | (1 << (id & 0xf));
+}
+
+static void guest_savic_apic_msr_accesses(int id)
+{
+ struct guest_apic_page *apage = get_guest_apic_page();
+ uint64_t val, hval;
+ uint32_t reg;
+ int vec;
+ int i;
+ uint32_t lvt_regs[] = {
+ APIC_LVTT, APIC_LVTTHMR, APIC_LVTPC,
+ APIC_LVT0, APIC_LVT1, APIC_LVTERR
+ };
+
+ reg = APIC_LVR;
+ val = savic_hv_read_reg(reg);
+ /* APIC_LVR state is in sync between host and guest. */
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_LVR");
+
+ reg = APIC_TASKPRI;
+ val = 0x30;
+ /* Write new TASKPRI to host using PV interface. */
+ savic_hv_write_reg(reg, val);
+ val = 0x40;
+ /* TASKPRI is accelerated and state is not up-to-date in host. */
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_TASKPRI");
+
+ reg = APIC_PROCPRI;
+ val = x2apic_read_reg(reg);
+ /* APIC_PROCPRI is updated with the APIC_TASKPRI update above. */
+ GUEST_ASSERT((val & 0xf0) == (x2apic_read_reg(APIC_TASKPRI) & 0xf0));
+ GUEST_ASSERT((val & 0xf0) == 0x40);
+ vec = 0x20;
+ x2apic_write_reg(APIC_ICR, APIC_DEST_SELF | APIC_INT_ASSERT | vec);
+ /* Interrupt remains pending in APIC_IRR. */
+ val = savic_read_reg(apage, APIC_IRR + APIC_REG_OFF(vec));
+ GUEST_ASSERT((val & BIT_ULL(APIC_VEC_POS(vec))) == BIT_ULL(APIC_VEC_POS(vec)));
+ savic_wrmsr(APIC_TASKPRI, 0x0);
+
+ /* Triggers GP fault */
+ savic_rdmsr(APIC_EOI);
+
+ reg = APIC_LDR;
+ val = x2apic_ldr(savic_rdmsr(APIC_ID));
+ hval = savic_hv_read_reg(APIC_LDR);
+ __GUEST_ASSERT(val == hval, "APIC_LDR mismatch between host %lx and guest %lx",
+ hval, val);
+
+ /* APIC_SPIV state is not visible to host. */
+ reg = APIC_SPIV;
+ val = savic_rdmsr(APIC_SPIV) & ~APIC_SPIV_APIC_ENABLED;
+ savic_hv_write_reg(reg, val);
+ val = savic_rdmsr(APIC_SPIV) | APIC_SPIV_APIC_ENABLED;
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_SPIV");
+
+ reg = APIC_ISR;
+ (void) savic_rdmsr(reg);
+ /* Triggers GP fault */
+ savic_wrmsr(reg, 0x10);
+
+ /* APIC_TMR is not synced to host. */
+ reg = APIC_TMR;
+ val = 0x10000;
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_TMR");
+ vec = 0x20;
+ savic_write_reg(apage, reg + APIC_REG_OFF(vec), BIT_ULL(APIC_VEC_POS(vec)));
+ GUEST_ASSERT(x2apic_read_reg(reg + APIC_REG_OFF(vec)) & BIT_ULL(APIC_VEC_POS(vec)));
+
+ reg = APIC_IRR;
+ val = 0x10000;
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_IRR");
+ savic_write_reg(apage, reg, 0x0);
+
+ reg = APIC_TMICT;
+ val = 0x555;
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_TMICT");
+
+ reg = APIC_TMCCT;
+ savic_rdmsr(reg);
+ savic_wrmsr(reg, 0xf);
+
+ reg = APIC_TDCR;
+ val = 0x1;
+ savic_hv_write_reg(reg, val);
+ val = 0x3;
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_TDCR");
+
+ for (i = 0; i < ARRAY_SIZE(lvt_regs); i++) {
+ reg = lvt_regs[i];
+ val = 0x41;
+ savic_hv_write_reg(reg, val);
+ val = 0x42;
+ guest_verify_host_guest_reg(apage, reg, val, "APIC_LVTx");
+ }
+}
+
static void guest_code(int id)
{
GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SNP_SECURE_AVIC);
@@ -302,6 +490,8 @@ static void guest_code(int id)
SAVIC_GUEST_SYNC(SAVIC_EN, guest_savic_enabled);
+ SAVIC_GUEST_SYNC(SAVIC_APIC_MSR_ACCESSES, guest_savic_apic_msr_accesses);
+
GUEST_DONE();
}
@@ -448,7 +638,7 @@ int main(int argc, char *argv[])
vcpu_args_set(vcpus[0], 1, vcpus[0]->id);
- vm_install_exception_handler(vm, 29, sev_es_vc_handler);
+ vm_install_exception_handler(vm, 29, savic_vc_handler);
vm_sev_launch(vm, snp_default_policy(), NULL);
r = pthread_create(&threads[0], NULL, vcpu_thread, vcpus[0]);
--
2.34.1
