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| author | Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> | 2016-08-23 13:52:41 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-09-08 12:57:20 +0200 |
| commit | 5ea11f2b31b83bd3c05357e6bec20f598e00705a (patch) | |
| tree | fd2f595fbac1d779f6764c4447c4457c30099a5c /arch/x86/kvm | |
| parent | 9ac7e3e815060efdc86b6d12448200e3c3597e01 (diff) | |
| download | linux-5ea11f2b31b83bd3c05357e6bec20f598e00705a.tar.bz2 | |
svm: Introduces AVIC per-VM ID
Introduces per-VM AVIC ID and helper functions to manage the IDs.
Currently, the ID will be used to implement 32-bit AVIC IOMMU GA tag.
The ID is 24-bit one-based indexing value, and is managed via helper
functions to get the next ID, or to free an ID once a VM is destroyed.
There should be no ID conflict for any active VMs.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/svm.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index af523d84d102..27e37d8044b3 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -96,6 +96,19 @@ MODULE_DEVICE_TABLE(x86cpu, svm_cpu_id); #define AVIC_UNACCEL_ACCESS_OFFSET_MASK 0xFF0 #define AVIC_UNACCEL_ACCESS_VECTOR_MASK 0xFFFFFFFF +/* AVIC GATAG is encoded using VM and VCPU IDs */ +#define AVIC_VCPU_ID_BITS 8 +#define AVIC_VCPU_ID_MASK ((1 << AVIC_VCPU_ID_BITS) - 1) + +#define AVIC_VM_ID_BITS 24 +#define AVIC_VM_ID_NR (1 << AVIC_VM_ID_BITS) +#define AVIC_VM_ID_MASK ((1 << AVIC_VM_ID_BITS) - 1) + +#define AVIC_GATAG(x, y) (((x & AVIC_VM_ID_MASK) << AVIC_VCPU_ID_BITS) | \ + (y & AVIC_VCPU_ID_MASK)) +#define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VCPU_ID_BITS) & AVIC_VM_ID_MASK) +#define AVIC_GATAG_TO_VCPUID(x) (x & AVIC_VCPU_ID_MASK) + static bool erratum_383_found __read_mostly; static const u32 host_save_user_msrs[] = { @@ -242,6 +255,10 @@ static int avic; module_param(avic, int, S_IRUGO); #endif +/* AVIC VM ID bit masks and lock */ +static DECLARE_BITMAP(avic_vm_id_bitmap, AVIC_VM_ID_NR); +static DEFINE_SPINLOCK(avic_vm_id_lock); + static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0); static void svm_flush_tlb(struct kvm_vcpu *vcpu); static void svm_complete_interrupts(struct vcpu_svm *svm); @@ -1280,10 +1297,40 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu) return 0; } +static inline int avic_get_next_vm_id(void) +{ + int id; + + spin_lock(&avic_vm_id_lock); + + /* AVIC VM ID is one-based. */ + id = find_next_zero_bit(avic_vm_id_bitmap, AVIC_VM_ID_NR, 1); + if (id <= AVIC_VM_ID_MASK) + __set_bit(id, avic_vm_id_bitmap); + else + id = -EAGAIN; + + spin_unlock(&avic_vm_id_lock); + return id; +} + +static inline int avic_free_vm_id(int id) +{ + if (id <= 0 || id > AVIC_VM_ID_MASK) + return -EINVAL; + + spin_lock(&avic_vm_id_lock); + __clear_bit(id, avic_vm_id_bitmap); + spin_unlock(&avic_vm_id_lock); + return 0; +} + static void avic_vm_destroy(struct kvm *kvm) { struct kvm_arch *vm_data = &kvm->arch; + avic_free_vm_id(vm_data->avic_vm_id); + if (vm_data->avic_logical_id_table_page) __free_page(vm_data->avic_logical_id_table_page); if (vm_data->avic_physical_id_table_page) @@ -1300,6 +1347,10 @@ static int avic_vm_init(struct kvm *kvm) if (!avic) return 0; + vm_data->avic_vm_id = avic_get_next_vm_id(); + if (vm_data->avic_vm_id < 0) + return vm_data->avic_vm_id; + /* Allocating physical APIC ID table (4KB) */ p_page = alloc_page(GFP_KERNEL); if (!p_page) |