KVM: VMX: Enable memory mapped TPR shadow (FlexPriority)
This patch based on CR8/TPR patch, and enable the TPR shadow (FlexPriority)
for 32bit Windows. Since TPR is accessed very frequently by 32bit
Windows, especially SMP guest, with FlexPriority enabled, we saw significant
performance gain.
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 516f79f..22317d6 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -383,6 +383,7 @@
struct kvm_ioapic *vioapic;
int round_robin_prev_vcpu;
unsigned int tss_addr;
+ struct page *apic_access_page;
};
static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
@@ -522,6 +523,9 @@
int kvm_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
int user_alloc);
+int __kvm_set_memory_region(struct kvm *kvm,
+ struct kvm_userspace_memory_region *mem,
+ int user_alloc);
gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn);
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
void kvm_release_page(struct page *page);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 8f71257..ac5ed00 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -362,10 +362,12 @@
* space.
*
* Discontiguous memory is allowed, mostly for framebuffers.
+ *
+ * Must be called holding kvm->lock.
*/
-int kvm_set_memory_region(struct kvm *kvm,
- struct kvm_userspace_memory_region *mem,
- int user_alloc)
+int __kvm_set_memory_region(struct kvm *kvm,
+ struct kvm_userspace_memory_region *mem,
+ int user_alloc)
{
int r;
gfn_t base_gfn;
@@ -392,8 +394,6 @@
if (!npages)
mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
- mutex_lock(&kvm->lock);
-
new = old = *memslot;
new.base_gfn = base_gfn;
@@ -403,7 +403,7 @@
/* Disallow changing a memory slot's size. */
r = -EINVAL;
if (npages && old.npages && npages != old.npages)
- goto out_unlock;
+ goto out_free;
/* Check for overlaps */
r = -EEXIST;
@@ -414,7 +414,7 @@
continue;
if (!((base_gfn + npages <= s->base_gfn) ||
(base_gfn >= s->base_gfn + s->npages)))
- goto out_unlock;
+ goto out_free;
}
/* Free page dirty bitmap if unneeded */
@@ -428,7 +428,7 @@
new.rmap = vmalloc(npages * sizeof(struct page *));
if (!new.rmap)
- goto out_unlock;
+ goto out_free;
memset(new.rmap, 0, npages * sizeof(*new.rmap));
@@ -445,7 +445,7 @@
up_write(¤t->mm->mmap_sem);
if (IS_ERR((void *)new.userspace_addr))
- goto out_unlock;
+ goto out_free;
}
} else {
if (!old.user_alloc && old.rmap) {
@@ -468,7 +468,7 @@
new.dirty_bitmap = vmalloc(dirty_bytes);
if (!new.dirty_bitmap)
- goto out_unlock;
+ goto out_free;
memset(new.dirty_bitmap, 0, dirty_bytes);
}
@@ -498,18 +498,28 @@
kvm_mmu_slot_remove_write_access(kvm, mem->slot);
kvm_flush_remote_tlbs(kvm);
- mutex_unlock(&kvm->lock);
-
kvm_free_physmem_slot(&old, &new);
return 0;
-out_unlock:
- mutex_unlock(&kvm->lock);
+out_free:
kvm_free_physmem_slot(&new, &old);
out:
return r;
}
+EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
+
+int kvm_set_memory_region(struct kvm *kvm,
+ struct kvm_userspace_memory_region *mem,
+ int user_alloc)
+{
+ int r;
+
+ mutex_lock(&kvm->lock);
+ r = __kvm_set_memory_region(kvm, mem, user_alloc);
+ mutex_unlock(&kvm->lock);
+ return r;
+}
EXPORT_SYMBOL_GPL(kvm_set_memory_region);
int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
@@ -888,14 +898,21 @@
memcpy(val, vcpu->mmio_data, bytes);
vcpu->mmio_read_completed = 0;
return X86EMUL_CONTINUE;
- } else if (emulator_read_std(addr, val, bytes, vcpu)
- == X86EMUL_CONTINUE)
- return X86EMUL_CONTINUE;
+ }
gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
+
+ /* For APIC access vmexit */
+ if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
+ goto mmio;
+
+ if (emulator_read_std(addr, val, bytes, vcpu)
+ == X86EMUL_CONTINUE)
+ return X86EMUL_CONTINUE;
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
+mmio:
/*
* Is this MMIO handled locally?
*/
@@ -938,9 +955,14 @@
return X86EMUL_PROPAGATE_FAULT;
}
+ /* For APIC access vmexit */
+ if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
+ goto mmio;
+
if (emulator_write_phys(vcpu, gpa, val, bytes))
return X86EMUL_CONTINUE;
+mmio:
/*
* Is this MMIO handled locally?
*/
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 7fe834c..eca422e 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -86,6 +86,7 @@
u32 revision_id;
u32 pin_based_exec_ctrl;
u32 cpu_based_exec_ctrl;
+ u32 cpu_based_2nd_exec_ctrl;
u32 vmexit_ctrl;
u32 vmentry_ctrl;
} vmcs_config;
@@ -179,6 +180,29 @@
return ((cpu_has_vmx_tpr_shadow()) && (irqchip_in_kernel(kvm)));
}
+static inline int cpu_has_secondary_exec_ctrls(void)
+{
+ return (vmcs_config.cpu_based_exec_ctrl &
+ CPU_BASED_ACTIVATE_SECONDARY_CONTROLS);
+}
+
+static inline int vm_need_secondary_exec_ctrls(struct kvm *kvm)
+{
+ return ((cpu_has_secondary_exec_ctrls()) && (irqchip_in_kernel(kvm)));
+}
+
+static inline int cpu_has_vmx_virtualize_apic_accesses(void)
+{
+ return (vmcs_config.cpu_based_2nd_exec_ctrl &
+ SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
+}
+
+static inline int vm_need_virtualize_apic_accesses(struct kvm *kvm)
+{
+ return ((cpu_has_vmx_virtualize_apic_accesses()) &&
+ (irqchip_in_kernel(kvm)));
+}
+
static int __find_msr_index(struct vcpu_vmx *vmx, u32 msr)
{
int i;
@@ -918,6 +942,7 @@
u32 min, opt;
u32 _pin_based_exec_control = 0;
u32 _cpu_based_exec_control = 0;
+ u32 _cpu_based_2nd_exec_control = 0;
u32 _vmexit_control = 0;
u32 _vmentry_control = 0;
@@ -935,11 +960,8 @@
CPU_BASED_USE_IO_BITMAPS |
CPU_BASED_MOV_DR_EXITING |
CPU_BASED_USE_TSC_OFFSETING;
-#ifdef CONFIG_X86_64
- opt = CPU_BASED_TPR_SHADOW;
-#else
- opt = 0;
-#endif
+ opt = CPU_BASED_TPR_SHADOW |
+ CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS,
&_cpu_based_exec_control) < 0)
return -EIO;
@@ -948,6 +970,18 @@
_cpu_based_exec_control &= ~CPU_BASED_CR8_LOAD_EXITING &
~CPU_BASED_CR8_STORE_EXITING;
#endif
+ if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) {
+ min = 0;
+ opt = SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
+ if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PROCBASED_CTLS2,
+ &_cpu_based_2nd_exec_control) < 0)
+ return -EIO;
+ }
+#ifndef CONFIG_X86_64
+ if (!(_cpu_based_2nd_exec_control &
+ SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES))
+ _cpu_based_exec_control &= ~CPU_BASED_TPR_SHADOW;
+#endif
min = 0;
#ifdef CONFIG_X86_64
@@ -985,6 +1019,7 @@
vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
+ vmcs_conf->cpu_based_2nd_exec_ctrl = _cpu_based_2nd_exec_control;
vmcs_conf->vmexit_ctrl = _vmexit_control;
vmcs_conf->vmentry_ctrl = _vmentry_control;
@@ -1427,6 +1462,27 @@
vmcs_write32(sf->ar_bytes, 0x93);
}
+static int alloc_apic_access_page(struct kvm *kvm)
+{
+ struct kvm_userspace_memory_region kvm_userspace_mem;
+ int r = 0;
+
+ mutex_lock(&kvm->lock);
+ if (kvm->apic_access_page)
+ goto out;
+ kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
+ kvm_userspace_mem.flags = 0;
+ kvm_userspace_mem.guest_phys_addr = 0xfee00000ULL;
+ kvm_userspace_mem.memory_size = PAGE_SIZE;
+ r = __kvm_set_memory_region(kvm, &kvm_userspace_mem, 0);
+ if (r)
+ goto out;
+ kvm->apic_access_page = gfn_to_page(kvm, 0xfee00);
+out:
+ mutex_unlock(&kvm->lock);
+ return r;
+}
+
/*
* Sets up the vmcs for emulated real mode.
*/
@@ -1458,8 +1514,14 @@
CPU_BASED_CR8_LOAD_EXITING;
#endif
}
+ if (!vm_need_secondary_exec_ctrls(vmx->vcpu.kvm))
+ exec_control &= ~CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, exec_control);
+ if (vm_need_secondary_exec_ctrls(vmx->vcpu.kvm))
+ vmcs_write32(SECONDARY_VM_EXEC_CONTROL,
+ vmcs_config.cpu_based_2nd_exec_ctrl);
+
vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK, !!bypass_guest_pf);
vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH, !!bypass_guest_pf);
vmcs_write32(CR3_TARGET_COUNT, 0); /* 22.2.1 */
@@ -1528,6 +1590,10 @@
vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);
vmcs_writel(CR4_GUEST_HOST_MASK, KVM_GUEST_CR4_MASK);
+ if (vm_need_virtualize_apic_accesses(vmx->vcpu.kvm))
+ if (alloc_apic_access_page(vmx->vcpu.kvm) != 0)
+ return -ENOMEM;
+
return 0;
}
@@ -1616,13 +1682,17 @@
vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0); /* 22.2.1 */
-#ifdef CONFIG_X86_64
- vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);
- if (vm_need_tpr_shadow(vmx->vcpu.kvm))
- vmcs_write64(VIRTUAL_APIC_PAGE_ADDR,
- page_to_phys(vmx->vcpu.apic->regs_page));
- vmcs_write32(TPR_THRESHOLD, 0);
-#endif
+ if (cpu_has_vmx_tpr_shadow()) {
+ vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, 0);
+ if (vm_need_tpr_shadow(vmx->vcpu.kvm))
+ vmcs_write64(VIRTUAL_APIC_PAGE_ADDR,
+ page_to_phys(vmx->vcpu.apic->regs_page));
+ vmcs_write32(TPR_THRESHOLD, 0);
+ }
+
+ if (vm_need_virtualize_apic_accesses(vmx->vcpu.kvm))
+ vmcs_write64(APIC_ACCESS_ADDR,
+ page_to_phys(vmx->vcpu.kvm->apic_access_page));
vmx->vcpu.cr0 = 0x60000010;
vmx_set_cr0(&vmx->vcpu, vmx->vcpu.cr0); /* enter rmode */
@@ -2094,6 +2164,26 @@
return 1;
}
+static int handle_apic_access(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+{
+ u64 exit_qualification;
+ enum emulation_result er;
+ unsigned long offset;
+
+ exit_qualification = vmcs_read64(EXIT_QUALIFICATION);
+ offset = exit_qualification & 0xffful;
+
+ er = emulate_instruction(vcpu, kvm_run, 0, 0, 0);
+
+ if (er != EMULATE_DONE) {
+ printk(KERN_ERR
+ "Fail to handle apic access vmexit! Offset is 0x%lx\n",
+ offset);
+ return -ENOTSUPP;
+ }
+ return 1;
+}
+
/*
* The exit handlers return 1 if the exit was handled fully and guest execution
* may resume. Otherwise they set the kvm_run parameter to indicate what needs
@@ -2113,7 +2203,8 @@
[EXIT_REASON_PENDING_INTERRUPT] = handle_interrupt_window,
[EXIT_REASON_HLT] = handle_halt,
[EXIT_REASON_VMCALL] = handle_vmcall,
- [EXIT_REASON_TPR_BELOW_THRESHOLD] = handle_tpr_below_threshold
+ [EXIT_REASON_TPR_BELOW_THRESHOLD] = handle_tpr_below_threshold,
+ [EXIT_REASON_APIC_ACCESS] = handle_apic_access,
};
static const int kvm_vmx_max_exit_handlers =
diff --git a/drivers/kvm/vmx.h b/drivers/kvm/vmx.h
index 270d477..c84bd37 100644
--- a/drivers/kvm/vmx.h
+++ b/drivers/kvm/vmx.h
@@ -89,6 +89,8 @@
TSC_OFFSET_HIGH = 0x00002011,
VIRTUAL_APIC_PAGE_ADDR = 0x00002012,
VIRTUAL_APIC_PAGE_ADDR_HIGH = 0x00002013,
+ APIC_ACCESS_ADDR = 0x00002014,
+ APIC_ACCESS_ADDR_HIGH = 0x00002015,
VMCS_LINK_POINTER = 0x00002800,
VMCS_LINK_POINTER_HIGH = 0x00002801,
GUEST_IA32_DEBUGCTL = 0x00002802,
@@ -214,6 +216,7 @@
#define EXIT_REASON_MSR_WRITE 32
#define EXIT_REASON_MWAIT_INSTRUCTION 36
#define EXIT_REASON_TPR_BELOW_THRESHOLD 43
+#define EXIT_REASON_APIC_ACCESS 44
/*
* Interruption-information format
@@ -307,4 +310,6 @@
#define MSR_IA32_FEATURE_CONTROL_LOCKED 0x1
#define MSR_IA32_FEATURE_CONTROL_VMXON_ENABLED 0x4
+#define APIC_ACCESS_PAGE_PRIVATE_MEMSLOT 9
+
#endif