Current SVM AVIC driver makes two incorrect assumptions:
1. APIC LDR register cannot be zero
2. APIC DFR for all vCPUs must be the same
LDR=0 means the local APIC does not support logical destination mode.
Therefore, the driver should mark any previously assigned logical APIC ID
table entry as invalid, and return success. Also, DFR is specific to
a particular local APIC, and can be different among all vCPUs
(as observed on Windows 10).
These incorrect assumptions cause Windows 10 and FreeBSD VMs to fail
to boot with AVIC enabled. So, instead of flush the whole logical APIC ID
table, handle DFR and LDR for each vCPU independently.
Fixes: 18f40c53e10f ('svm: Add VMEXIT handlers for AVIC')
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Julian Stecklina <jsteckli@amazon.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
/* Struct members for AVIC */
u32 avic_vm_id;
/* Struct members for AVIC */
u32 avic_vm_id;
struct page *avic_logical_id_table_page;
struct page *avic_physical_id_table_page;
struct hlist_node hnode;
struct page *avic_logical_id_table_page;
struct page *avic_physical_id_table_page;
struct hlist_node hnode;
bool nrips_enabled : 1;
u32 ldr_reg;
bool nrips_enabled : 1;
u32 ldr_reg;
struct page *avic_backing_page;
u64 *avic_physical_id_cache;
bool avic_is_running;
struct page *avic_backing_page;
u64 *avic_physical_id_cache;
bool avic_is_running;
INIT_LIST_HEAD(&svm->ir_list);
spin_lock_init(&svm->ir_list_lock);
INIT_LIST_HEAD(&svm->ir_list);
spin_lock_init(&svm->ir_list_lock);
+ svm->dfr_reg = APIC_DFR_FLAT;
return &logical_apic_id_table[index];
}
return &logical_apic_id_table[index];
}
-static int avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr,
- bool valid)
+static int avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr)
{
bool flat;
u32 *entry, new_entry;
{
bool flat;
u32 *entry, new_entry;
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);
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;
+ new_entry |= AVIC_LOGICAL_ID_ENTRY_VALID_MASK;
WRITE_ONCE(*entry, new_entry);
return 0;
}
WRITE_ONCE(*entry, new_entry);
return 0;
}
+static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ bool flat = svm->dfr_reg == APIC_DFR_FLAT;
+ u32 *entry = avic_get_logical_id_entry(vcpu, svm->ldr_reg, flat);
+
+ if (entry)
+ WRITE_ONCE(*entry, (u32) ~AVIC_LOGICAL_ID_ENTRY_VALID_MASK);
+}
+
static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
{
static int avic_handle_ldr_update(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR);
struct vcpu_svm *svm = to_svm(vcpu);
u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR);
+ if (ldr == svm->ldr_reg)
+ return 0;
- 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 {
+ avic_invalidate_logical_id_entry(vcpu);
+
+ if (ldr)
+ ret = avic_ldr_write(vcpu, vcpu->vcpu_id, ldr);
+
+ if (!ret)
-static int avic_handle_dfr_update(struct kvm_vcpu *vcpu)
+static void avic_handle_dfr_update(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm);
u32 dfr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR);
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 (kvm_svm->ldr_mode == mod)
- return 0;
- clear_page(page_address(kvm_svm->avic_logical_id_table_page));
- kvm_svm->ldr_mode = mod;
+ if (svm->dfr_reg == dfr)
+ return;
- if (svm->ldr_reg)
- avic_handle_ldr_update(vcpu);
- return 0;
+ avic_invalidate_logical_id_entry(vcpu);
+ svm->dfr_reg = dfr;
}
static int avic_unaccel_trap_write(struct vcpu_svm *svm)
}
static int avic_unaccel_trap_write(struct vcpu_svm *svm)
{
if (avic_handle_apic_id_update(vcpu) != 0)
return;
{
if (avic_handle_apic_id_update(vcpu) != 0)
return;
- if (avic_handle_dfr_update(vcpu) != 0)
- return;
+ avic_handle_dfr_update(vcpu);
avic_handle_ldr_update(vcpu);
}
avic_handle_ldr_update(vcpu);
}