svm: Add VMEXIT handlers for AVIC
This patch introduces VMEXIT handlers, avic_incomplete_ipi_interception()
and avic_unaccelerated_access_interception() along with two trace points
(trace_kvm_avic_incomplete_ipi and trace_kvm_avic_unaccelerated_access).
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 95d9b5c..db2c140 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -91,6 +91,10 @@
*/
#define AVIC_MAX_PHYSICAL_ID_COUNT 255
+#define AVIC_UNACCEL_ACCESS_WRITE_MASK 1
+#define AVIC_UNACCEL_ACCESS_OFFSET_MASK 0xFF0
+#define AVIC_UNACCEL_ACCESS_VECTOR_MASK 0xFFFFFFFF
+
static bool erratum_383_found __read_mostly;
static const u32 host_save_user_msrs[] = {
@@ -176,6 +180,7 @@
/* cached guest cpuid flags for faster access */
bool nrips_enabled : 1;
+ u32 ldr_reg;
struct page *avic_backing_page;
u64 *avic_physical_id_cache;
};
@@ -3492,6 +3497,278 @@
return nop_interception(svm);
}
+enum avic_ipi_failure_cause {
+ AVIC_IPI_FAILURE_INVALID_INT_TYPE,
+ AVIC_IPI_FAILURE_TARGET_NOT_RUNNING,
+ AVIC_IPI_FAILURE_INVALID_TARGET,
+ AVIC_IPI_FAILURE_INVALID_BACKING_PAGE,
+};
+
+static int avic_incomplete_ipi_interception(struct vcpu_svm *svm)
+{
+ u32 icrh = svm->vmcb->control.exit_info_1 >> 32;
+ u32 icrl = svm->vmcb->control.exit_info_1;
+ u32 id = svm->vmcb->control.exit_info_2 >> 32;
+ u32 index = svm->vmcb->control.exit_info_2 && 0xFF;
+ struct kvm_lapic *apic = svm->vcpu.arch.apic;
+
+ trace_kvm_avic_incomplete_ipi(svm->vcpu.vcpu_id, icrh, icrl, id, index);
+
+ switch (id) {
+ case AVIC_IPI_FAILURE_INVALID_INT_TYPE:
+ /*
+ * AVIC hardware handles the generation of
+ * IPIs when the specified Message Type is Fixed
+ * (also known as fixed delivery mode) and
+ * the Trigger Mode is edge-triggered. The hardware
+ * also supports self and broadcast delivery modes
+ * specified via the Destination Shorthand(DSH)
+ * field of the ICRL. Logical and physical APIC ID
+ * formats are supported. All other IPI types cause
+ * a #VMEXIT, which needs to emulated.
+ */
+ kvm_lapic_reg_write(apic, APIC_ICR2, icrh);
+ kvm_lapic_reg_write(apic, APIC_ICR, icrl);
+ break;
+ case AVIC_IPI_FAILURE_TARGET_NOT_RUNNING: {
+ int i;
+ struct kvm_vcpu *vcpu;
+ struct kvm *kvm = svm->vcpu.kvm;
+ struct kvm_lapic *apic = svm->vcpu.arch.apic;
+
+ /*
+ * At this point, we expect that the AVIC HW has already
+ * set the appropriate IRR bits on the valid target
+ * vcpus. So, we just need to kick the appropriate vcpu.
+ */
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ bool m = kvm_apic_match_dest(vcpu, apic,
+ icrl & KVM_APIC_SHORT_MASK,
+ GET_APIC_DEST_FIELD(icrh),
+ icrl & KVM_APIC_DEST_MASK);
+
+ if (m && !avic_vcpu_is_running(vcpu))
+ kvm_vcpu_wake_up(vcpu);
+ }
+ break;
+ }
+ case AVIC_IPI_FAILURE_INVALID_TARGET:
+ break;
+ case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE:
+ WARN_ONCE(1, "Invalid backing page\n");
+ break;
+ default:
+ pr_err("Unknown IPI interception\n");
+ }
+
+ return 1;
+}
+
+static u32 *avic_get_logical_id_entry(struct kvm_vcpu *vcpu, u32 ldr, bool flat)
+{
+ struct kvm_arch *vm_data = &vcpu->kvm->arch;
+ int index;
+ u32 *logical_apic_id_table;
+ int dlid = GET_APIC_LOGICAL_ID(ldr);
+
+ if (!dlid)
+ return NULL;
+
+ if (flat) { /* flat */
+ index = ffs(dlid) - 1;
+ if (index > 7)
+ return NULL;
+ } else { /* cluster */
+ int cluster = (dlid & 0xf0) >> 4;
+ int apic = ffs(dlid & 0x0f) - 1;
+
+ if ((apic < 0) || (apic > 7) ||
+ (cluster >= 0xf))
+ return NULL;
+ index = (cluster << 2) + apic;
+ }
+
+ logical_apic_id_table = (u32 *) page_address(vm_data->avic_logical_id_table_page);
+
+ return &logical_apic_id_table[index];
+}
+
+static int avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr,
+ bool valid)
+{
+ bool flat;
+ u32 *entry, new_entry;
+
+ flat = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR) == APIC_DFR_FLAT;
+ entry = avic_get_logical_id_entry(vcpu, ldr, flat);
+ if (!entry)
+ return -EINVAL;
+
+ new_entry = READ_ONCE(*entry);
+ new_entry &= ~AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK;
+ new_entry |= (g_physical_id & AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK);
+ if (valid)
+ new_entry |= AVIC_LOGICAL_ID_ENTRY_VALID_MASK;
+ else
+ new_entry &= ~AVIC_LOGICAL_ID_ENTRY_VALID_MASK;
+ WRITE_ONCE(*entry, new_entry);
+
+ return 0;
+}
+
+static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
+{
+ int ret;
+ struct vcpu_svm *svm = to_svm(vcpu);
+ u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR);
+
+ if (!ldr)
+ return 1;
+
+ ret = avic_ldr_write(vcpu, vcpu->vcpu_id, ldr, true);
+ if (ret && svm->ldr_reg) {
+ avic_ldr_write(vcpu, 0, svm->ldr_reg, false);
+ svm->ldr_reg = 0;
+ } else {
+ svm->ldr_reg = ldr;
+ }
+ return ret;
+}
+
+static int avic_handle_apic_id_update(struct kvm_vcpu *vcpu)
+{
+ u64 *old, *new;
+ struct vcpu_svm *svm = to_svm(vcpu);
+ u32 apic_id_reg = kvm_lapic_get_reg(vcpu->arch.apic, APIC_ID);
+ u32 id = (apic_id_reg >> 24) & 0xff;
+
+ if (vcpu->vcpu_id == id)
+ return 0;
+
+ old = avic_get_physical_id_entry(vcpu, vcpu->vcpu_id);
+ new = avic_get_physical_id_entry(vcpu, id);
+ if (!new || !old)
+ return 1;
+
+ /* We need to move physical_id_entry to new offset */
+ *new = *old;
+ *old = 0ULL;
+ to_svm(vcpu)->avic_physical_id_cache = new;
+
+ /*
+ * Also update the guest physical APIC ID in the logical
+ * APIC ID table entry if already setup the LDR.
+ */
+ if (svm->ldr_reg)
+ avic_handle_ldr_update(vcpu);
+
+ return 0;
+}
+
+static int avic_handle_dfr_update(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ struct kvm_arch *vm_data = &vcpu->kvm->arch;
+ u32 dfr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR);
+ u32 mod = (dfr >> 28) & 0xf;
+
+ /*
+ * We assume that all local APICs are using the same type.
+ * If this changes, we need to flush the AVIC logical
+ * APID id table.
+ */
+ if (vm_data->ldr_mode == mod)
+ return 0;
+
+ clear_page(page_address(vm_data->avic_logical_id_table_page));
+ vm_data->ldr_mode = mod;
+
+ if (svm->ldr_reg)
+ avic_handle_ldr_update(vcpu);
+ return 0;
+}
+
+static int avic_unaccel_trap_write(struct vcpu_svm *svm)
+{
+ struct kvm_lapic *apic = svm->vcpu.arch.apic;
+ u32 offset = svm->vmcb->control.exit_info_1 &
+ AVIC_UNACCEL_ACCESS_OFFSET_MASK;
+
+ switch (offset) {
+ case APIC_ID:
+ if (avic_handle_apic_id_update(&svm->vcpu))
+ return 0;
+ break;
+ case APIC_LDR:
+ if (avic_handle_ldr_update(&svm->vcpu))
+ return 0;
+ break;
+ case APIC_DFR:
+ avic_handle_dfr_update(&svm->vcpu);
+ break;
+ default:
+ break;
+ }
+
+ kvm_lapic_reg_write(apic, offset, kvm_lapic_get_reg(apic, offset));
+
+ return 1;
+}
+
+static bool is_avic_unaccelerated_access_trap(u32 offset)
+{
+ bool ret = false;
+
+ switch (offset) {
+ case APIC_ID:
+ case APIC_EOI:
+ case APIC_RRR:
+ case APIC_LDR:
+ case APIC_DFR:
+ case APIC_SPIV:
+ case APIC_ESR:
+ case APIC_ICR:
+ case APIC_LVTT:
+ case APIC_LVTTHMR:
+ case APIC_LVTPC:
+ case APIC_LVT0:
+ case APIC_LVT1:
+ case APIC_LVTERR:
+ case APIC_TMICT:
+ case APIC_TDCR:
+ ret = true;
+ break;
+ default:
+ break;
+ }
+ return ret;
+}
+
+static int avic_unaccelerated_access_interception(struct vcpu_svm *svm)
+{
+ int ret = 0;
+ u32 offset = svm->vmcb->control.exit_info_1 &
+ AVIC_UNACCEL_ACCESS_OFFSET_MASK;
+ u32 vector = svm->vmcb->control.exit_info_2 &
+ AVIC_UNACCEL_ACCESS_VECTOR_MASK;
+ bool write = (svm->vmcb->control.exit_info_1 >> 32) &
+ AVIC_UNACCEL_ACCESS_WRITE_MASK;
+ bool trap = is_avic_unaccelerated_access_trap(offset);
+
+ trace_kvm_avic_unaccelerated_access(svm->vcpu.vcpu_id, offset,
+ trap, write, vector);
+ if (trap) {
+ /* Handling Trap */
+ WARN_ONCE(!write, "svm: Handling trap read.\n");
+ ret = avic_unaccel_trap_write(svm);
+ } else {
+ /* Handling Fault */
+ ret = (emulate_instruction(&svm->vcpu, 0) == EMULATE_DONE);
+ }
+
+ return ret;
+}
+
static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_READ_CR0] = cr_interception,
[SVM_EXIT_READ_CR3] = cr_interception,
@@ -3555,6 +3832,8 @@
[SVM_EXIT_XSETBV] = xsetbv_interception,
[SVM_EXIT_NPF] = pf_interception,
[SVM_EXIT_RSM] = emulate_on_interception,
+ [SVM_EXIT_AVIC_INCOMPLETE_IPI] = avic_incomplete_ipi_interception,
+ [SVM_EXIT_AVIC_UNACCELERATED_ACCESS] = avic_unaccelerated_access_interception,
};
static void dump_vmcb(struct kvm_vcpu *vcpu)