This patch introduces AVIC-related data structure, and AVIC
initialization code.
There are three main data structures for AVIC:
* Virtual APIC (vAPIC) backing page (per-VCPU)
* Physical APIC ID table (per-VM)
* Logical APIC ID table (per-VM)
In order to accommodate the new per-VM tables, we introduce
a new per-VM arch-specific void pointer, struct kvm_arch.arch_data.
This will point to the newly introduced struct svm_vm_data.
Currently, AVIC is disabled by default. Users can manually
enable AVIC via kernel boot option kvm-amd.avic=1 or during
kvm-amd module loading with parameter avic=1.
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
arch/x86/include/asm/kvm_host.h | 2 +
arch/x86/kvm/svm.c | 416 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 417 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9a61669..15f6cd8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -754,6 +754,8 @@ struct kvm_arch {
bool irqchip_split;
u8 nr_reserved_ioapic_pins;
+
+ void *arch_data;
};
struct kvm_vm_stat {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6ab66d0..c703149 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -14,6 +14,9 @@
* the COPYING file in the top-level directory.
*
*/
+
+#define pr_fmt(fmt) "SVM: " fmt
+
#include <linux/kvm_host.h>
#include "irq.h"
@@ -78,6 +81,11 @@ MODULE_DEVICE_TABLE(x86cpu, svm_cpu_id);
#define TSC_RATIO_MIN 0x0000000000000001ULL
#define TSC_RATIO_MAX 0x000000ffffffffffULL
+#define AVIC_HPA_MASK ~((0xFFFULL << 52) || 0xFFF)
+
+/* NOTE: Current max index allowed for physical APIC ID table is 255 */
+#define AVIC_PHY_APIC_ID_MAX 0xFF
+
static bool erratum_383_found __read_mostly;
static const u32 host_save_user_msrs[] = {
@@ -162,6 +170,37 @@ struct vcpu_svm {
/* cached guest cpuid flags for faster access */
bool nrips_enabled : 1;
+
+ struct page *avic_bk_page;
+ void *in_kernel_lapic_regs;
+};
+
+struct __attribute__ ((__packed__))
+svm_avic_log_ait_entry {
+ u32 guest_phy_apic_id : 8,
+ res : 23,
+ valid : 1;
+};
+
+struct __attribute__ ((__packed__))
+svm_avic_phy_ait_entry {
+ u64 host_phy_apic_id : 8,
+ res1 : 4,
+ bk_pg_ptr : 40,
+ res2 : 10,
+ is_running : 1,
+ valid : 1;
+};
+
+/* Note: This structure is per VM */
+struct svm_vm_data {
+ atomic_t count;
+ u32 ldr_mode;
+ u32 avic_max_vcpu_id;
+ u32 avic_tag;
+
+ struct page *avic_log_ait_page;
+ struct page *avic_phy_ait_page;
};
static DEFINE_PER_CPU(u64, current_tsc_ratio);
@@ -205,6 +244,10 @@ module_param(npt, int, S_IRUGO);
static int nested = true;
module_param(nested, int, S_IRUGO);
+/* enable / disable AVIC */
+static int avic;
+module_param(avic, int, S_IRUGO);
+
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);
@@ -234,6 +277,13 @@ enum {
/* TPR and CR2 are always written before VMRUN */
#define VMCB_ALWAYS_DIRTY_MASK ((1U << VMCB_INTR) | (1U << VMCB_CR2))
+#define VMCB_AVIC_APIC_BAR_MASK 0xFFFFFFFFFF000ULL
+
+static inline void avic_update_vapic_bar(struct vcpu_svm *svm, u64 data)
+{
+ svm->vmcb->control.avic_vapic_bar = data & VMCB_AVIC_APIC_BAR_MASK;
+}
+
static inline void mark_all_dirty(struct vmcb *vmcb)
{
vmcb->control.clean = 0;
@@ -923,6 +973,13 @@ static __init int svm_hardware_setup(void)
} else
kvm_disable_tdp();
+ if (avic && (!npt_enabled || !boot_cpu_has(X86_FEATURE_AVIC)))
+ avic = false;
+
+ if (avic) {
+ printk(KERN_INFO "kvm: AVIC enabled\n");
+ }
+
return 0;
err:
@@ -1000,6 +1057,41 @@ static void svm_adjust_tsc_offset_guest(struct kvm_vcpu
*vcpu, s64 adjustment)
mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
}
+static void avic_init_vmcb(struct vcpu_svm *svm)
+{
+ void *vapic_bkpg;
+ struct vmcb *vmcb = svm->vmcb;
+ struct svm_vm_data *vm_data = svm->vcpu.kvm->arch.arch_data;
+ phys_addr_t bpa = PFN_PHYS(page_to_pfn(svm->avic_bk_page));
+ phys_addr_t lpa = PFN_PHYS(page_to_pfn(vm_data->avic_log_ait_page));
+ phys_addr_t ppa = PFN_PHYS(page_to_pfn(vm_data->avic_phy_ait_page));
+
+ if (!vmcb)
+ return;
+
+ pr_debug("%s: bpa=%#llx, lpa=%#llx, ppa=%#llx\n",
+ __func__, (unsigned long long)bpa,
+ (unsigned long long)lpa, (unsigned long long)ppa);
+
+
+ /*
+ * Here we copy the value from the emulated LAPIC register
+ * to the vAPIC backign page, and then flip regs frame.
+ */
+ if (!svm->in_kernel_lapic_regs)
+ svm->in_kernel_lapic_regs = svm->vcpu.arch.apic->regs;
+
+ vapic_bkpg = pfn_to_kaddr(page_to_pfn(svm->avic_bk_page));
+ memcpy(vapic_bkpg, svm->in_kernel_lapic_regs, PAGE_SIZE);
+ svm->vcpu.arch.apic->regs = vapic_bkpg;
+
+ vmcb->control.avic_bk_page = bpa & AVIC_HPA_MASK;
+ vmcb->control.avic_log_apic_id = lpa & AVIC_HPA_MASK;
+ vmcb->control.avic_phy_apic_id = ppa & AVIC_HPA_MASK;
+ vmcb->control.avic_phy_apic_id |= AVIC_PHY_APIC_ID_MAX;
+ vmcb->control.avic_enable = 1;
+}
+
static void init_vmcb(struct vcpu_svm *svm)
{
struct vmcb_control_area *control = &svm->vmcb->control;
@@ -1113,6 +1205,293 @@ static void init_vmcb(struct vcpu_svm *svm)
mark_all_dirty(svm->vmcb);
enable_gif(svm);
+
+ if (avic)
+ avic_init_vmcb(svm);
+}
+
+static struct svm_avic_phy_ait_entry *
+avic_get_phy_ait_entry(struct kvm_vcpu *vcpu, int index)
+{
+ struct svm_avic_phy_ait_entry *avic_phy_ait;
+ struct svm_vm_data *vm_data = vcpu->kvm->arch.arch_data;
+
+ if (!vm_data)
+ return NULL;
+
+ /* Note: APIC ID = 0xff is used for broadcast.
+ * APIC ID > 0xff is reserved.
+ */
+ if (index >= 0xff)
+ return NULL;
+
+ avic_phy_ait = page_address(vm_data->avic_phy_ait_page);
+
+ return &avic_phy_ait[index];
+}
+
+struct svm_avic_log_ait_entry *
+avic_get_log_ait_entry(struct kvm_vcpu *vcpu, u8 mda, bool is_flat)
+{
+ struct svm_vm_data *vm_data = vcpu->kvm->arch.arch_data;
+ int index;
+ struct svm_avic_log_ait_entry *avic_log_ait;
+
+ if (!vm_data)
+ return NULL;
+
+ if (is_flat) { /* flat */
+ if (mda > 7)
+ return NULL;
+ index = mda;
+ } else { /* cluster */
+ int apic_id = mda & 0xf;
+ int cluster_id = (mda & 0xf0) >> 8;
+
+ if (apic_id > 4 || cluster_id >= 0xf)
+ return NULL;
+ index = (cluster_id << 2) + apic_id;
+ }
+ avic_log_ait = (struct svm_avic_log_ait_entry *)
+ page_address(vm_data->avic_log_ait_page);
+
+ return &avic_log_ait[index];
+}
+
+static inline void
+avic_set_bk_page_entry(struct vcpu_svm *svm, int reg_off, u32 val)
+{
+ void *avic_bk = page_address(svm->avic_bk_page);
+
+ *((u32 *) (avic_bk + reg_off)) = val;
+}
+
+static inline u32 *avic_get_bk_page_entry(struct vcpu_svm *svm, u32 offset)
+{
+ char *tmp = (char *)page_address(svm->avic_bk_page);
+
+ return (u32 *)(tmp+offset);
+}
+
+static int avic_init_log_apic_entry(struct kvm_vcpu *vcpu, u8 g_phy_apic_id,
+ u8 log_apic_id)
+{
+ u32 mod;
+ struct svm_avic_log_ait_entry *entry;
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ if (!svm)
+ return -EINVAL;
+
+ mod = (*avic_get_bk_page_entry(svm, APIC_DFR) >> 28) & 0xf;
+ entry = avic_get_log_ait_entry(vcpu, log_apic_id, (mod == 0xf));
+ if (!entry)
+ return -EINVAL;
+ entry->guest_phy_apic_id = g_phy_apic_id;
+ entry->valid = 1;
+
+ return 0;
+}
+
+static int avic_init_bk_page(struct kvm_vcpu *vcpu)
+{
+ u64 addr;
+ struct page *page;
+ int id = vcpu->vcpu_id;
+ struct kvm *kvm = vcpu->kvm;
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ addr = APIC_DEFAULT_PHYS_BASE + (id * PAGE_SIZE);
+ page = gfn_to_page(kvm, addr >> PAGE_SHIFT);
+ if (is_error_page(page))
+ return -EFAULT;
+
+ /*
+ * Do not pin the page in memory, so that memory hot-unplug
+ * is able to migrate it.
+ */
+ put_page(page);
+
+ /* Setting up AVIC Backing Page */
+ svm->avic_bk_page = page;
+
+ clear_page(kmap(page));
+ pr_debug("%s: vAPIC bk page: cpu=%u, addr=%#llx, pa=%#llx\n",
+ __func__, id, addr,
+ (unsigned long long) PFN_PHYS(page_to_pfn(page)));
+
+ avic_init_vmcb(svm);
+
+ return 0;
+}
+
+static inline void avic_unalloc_bk_page(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ if (svm->avic_bk_page)
+ kunmap(svm->avic_bk_page);
+}
+
+static int avic_alloc_bk_page(struct vcpu_svm *svm, int id)
+{
+ int ret = 0, i;
+ bool realloc = false;
+ struct kvm_vcpu *vcpu;
+ struct kvm *kvm = svm->vcpu.kvm;
+ struct svm_vm_data *vm_data = kvm->arch.arch_data;
+
+ mutex_lock(&kvm->slots_lock);
+
+ /* Check if we have already allocated vAPIC backing
+ * page for this vCPU. If not, we need to realloc
+ * a new one and re-assign all other vCPU.
+ */
+ if (kvm->arch.apic_access_page_done &&
+ (id > vm_data->avic_max_vcpu_id)) {
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ avic_unalloc_bk_page(vcpu);
+
+ __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
+ 0, 0);
+ realloc = true;
+ vm_data->avic_max_vcpu_id = 0;
+ }
+
+ /*
+ * We are allocating vAPIC backing page
+ * upto the max vCPU ID
+ */
+ if (id >= vm_data->avic_max_vcpu_id) {
+ ret = __x86_set_memory_region(kvm,
+ APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
+ APIC_DEFAULT_PHYS_BASE,
+ PAGE_SIZE * (id + 1));
+ if (ret)
+ goto out;
+
+ vm_data->avic_max_vcpu_id = id;
+ }
+
+ /* Reinit vAPIC backing page for exisinting vcpus */
+ if (realloc)
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ avic_init_bk_page(vcpu);
+
+ avic_init_bk_page(&svm->vcpu);
+
+ kvm->arch.apic_access_page_done = true;
+
+out:
+ mutex_unlock(&kvm->slots_lock);
+ return ret;
+}
+
+static void avic_vm_uninit(struct kvm *kvm)
+{
+ struct svm_vm_data *vm_data = kvm->arch.arch_data;
+
+ if (!vm_data)
+ return;
+
+ if (vm_data->avic_log_ait_page)
+ __free_page(vm_data->avic_log_ait_page);
+ if (vm_data->avic_phy_ait_page)
+ __free_page(vm_data->avic_phy_ait_page);
+ kfree(vm_data);
+ kvm->arch.arch_data = NULL;
+}
+
+static void avic_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ struct svm_vm_data *vm_data = vcpu->kvm->arch.arch_data;
+
+ if (!avic)
+ return;
+
+ avic_unalloc_bk_page(vcpu);
+ svm->vcpu.arch.apic->regs = svm->in_kernel_lapic_regs;
+ svm->in_kernel_lapic_regs = NULL;
+
+ if (vm_data &&
+ (atomic_read(&vm_data->count) == 0 ||
+ atomic_dec_and_test(&vm_data->count)))
+ avic_vm_uninit(vcpu->kvm);
+}
+
+static atomic_t avic_tag_gen = ATOMIC_INIT(1);
+
+static inline u32 avic_get_next_tag(void)
+{
+ u32 tag = atomic_read(&avic_tag_gen);
+
+ atomic_inc(&avic_tag_gen);
+ return tag;
+}
+
+static int avic_vm_init(struct kvm *kvm)
+{
+ int err = -ENOMEM;
+ struct svm_vm_data *vm_data;
+ struct page *avic_phy_ait_page;
+ struct page *avic_log_ait_page;
+
+ vm_data = kzalloc(sizeof(struct svm_vm_data),
+ GFP_KERNEL);
+ if (!vm_data)
+ return err;
+
+ kvm->arch.arch_data = vm_data;
+ atomic_set(&vm_data->count, 0);
+
+ /* Allocating physical APIC ID table (4KB) */
+ avic_phy_ait_page = alloc_page(GFP_KERNEL);
+ if (!avic_phy_ait_page)
+ goto free_avic;
+
+ vm_data->avic_phy_ait_page = avic_phy_ait_page;
+ clear_page(page_address(avic_phy_ait_page));
+
+ /* Allocating logical APIC ID table (4KB) */
+ avic_log_ait_page = alloc_page(GFP_KERNEL);
+ if (!avic_log_ait_page)
+ goto free_avic;
+
+ vm_data->avic_log_ait_page = avic_log_ait_page;
+ clear_page(page_address(avic_log_ait_page));
+
+ vm_data->avic_tag = avic_get_next_tag();
+
+ return 0;
+
+free_avic:
+ avic_vm_uninit(kvm);
+ return err;
+}
+
+static int avic_vcpu_init(struct kvm *kvm, struct vcpu_svm *svm, int id)
+{
+ int err;
+ struct svm_vm_data *vm_data = NULL;
+
+ /* Note: svm_vm_data is per VM */
+ if (!kvm->arch.arch_data) {
+ err = avic_vm_init(kvm);
+ if (err)
+ return err;
+ }
+
+ err = avic_alloc_bk_page(svm, id);
+ if (err) {
+ avic_vcpu_uninit(&svm->vcpu);
+ return err;
+ }
+
+ vm_data = kvm->arch.arch_data;
+ atomic_inc(&vm_data->count);
+
+ return 0;
}
static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
@@ -1131,6 +1510,9 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool
init_event)
kvm_cpuid(vcpu, &eax, &dummy, &dummy, &dummy);
kvm_register_write(vcpu, VCPU_REGS_RDX, eax);
+
+ if (avic && !init_event)
+ avic_update_vapic_bar(svm, APIC_DEFAULT_PHYS_BASE);
}
static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
@@ -1169,6 +1551,12 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm,
unsigned int id)
if (!hsave_page)
goto free_page3;
+ if (avic) {
+ err = avic_vcpu_init(kvm, svm, id);
+ if (err)
+ goto free_page4;
+ }
+
svm->nested.hsave = page_address(hsave_page);
svm->msrpm = page_address(msrpm_pages);
@@ -1187,6 +1575,8 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm,
unsigned int id)
return &svm->vcpu;
+free_page4:
+ __free_page(hsave_page);
free_page3:
__free_pages(nested_msrpm_pages, MSRPM_ALLOC_ORDER);
free_page2:
@@ -1209,6 +1599,7 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
__free_pages(virt_to_page(svm->msrpm), MSRPM_ALLOC_ORDER);
__free_page(virt_to_page(svm->nested.hsave));
__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
+ avic_vcpu_uninit(vcpu);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, svm);
}
@@ -3382,6 +3773,7 @@ static void dump_vmcb(struct kvm_vcpu *vcpu)
pr_err("%-20s%08x\n", "exit_int_info_err:", control->exit_int_info_err);
pr_err("%-20s%lld\n", "nested_ctl:", control->nested_ctl);
pr_err("%-20s%016llx\n", "nested_cr3:", control->nested_cr3);
+ pr_err("%-20s%016llx\n", "avic_vapic_bar:", control->avic_vapic_bar);
pr_err("%-20s%08x\n", "event_inj:", control->event_inj);
pr_err("%-20s%08x\n", "event_inj_err:", control->event_inj_err);
pr_err("%-20s%lld\n", "lbr_ctl:", control->lbr_ctl);
@@ -3613,11 +4005,31 @@ static void svm_set_virtual_x2apic_mode(struct kvm_vcpu
*vcpu, bool set)
static bool svm_get_enable_apicv(void)
{
- return false;
+ return avic;
+}
+
+static void svm_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr)
+{
}
+static void svm_hwapic_isr_update(struct kvm *kvm, int isr)
+{
+}
+
+/* Note: Currently only used by Hyper-V. */
static void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ struct vmcb *vmcb = svm->vmcb;
+
+ if (!avic)
+ return;
+
+ if (!svm->in_kernel_lapic_regs)
+ return;
+
+ svm->vcpu.arch.apic->regs = svm->in_kernel_lapic_regs;
+ vmcb->control.avic_enable = 0;
}
static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
@@ -4387,6 +4799,8 @@ static struct kvm_x86_ops svm_x86_ops = {
.refresh_apicv_exec_ctrl = svm_refresh_apicv_exec_ctrl,
.load_eoi_exitmap = svm_load_eoi_exitmap,
.sync_pir_to_irr = svm_sync_pir_to_irr,
+ .hwapic_irr_update = svm_hwapic_irr_update,
+ .hwapic_isr_update = svm_hwapic_isr_update,
.set_tss_addr = svm_set_tss_addr,
.get_tdp_level = get_npt_level,
--
1.9.1
