>From 2fc9eedaaaf4034c2b84ee0b3b0c8153f775545d Mon Sep 17 00:00:00 2001
From: Sheng Yang <[EMAIL PROTECTED]>
Date: Fri, 26 Oct 2007 13:43:11 +0800
Subject: [PATCH] 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 <[EMAIL PROTECTED]>
---
 drivers/kvm/kvm.h      |    1 +
 drivers/kvm/kvm_main.c |   18 ++++++-
 drivers/kvm/vmx.c      |  116
++++++++++++++++++++++++++++++++++++++++++-----
 drivers/kvm/vmx.h      |    3 +
 4 files changed, 122 insertions(+), 16 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index b08fc9e..31b2dd7 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -384,6 +384,7 @@ struct kvm {
        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)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 9a3d663..506bebb 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1293,14 +1293,21 @@ static int emulator_read_emulated(unsigned long
addr,
                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?
         */
@@ -1343,9 +1350,14 @@ static int
emulator_write_emulated_onepage(unsigned long addr,
                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 e239fc2..789b72d 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -86,6 +86,7 @@ static struct vmcs_config {
        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 @@ static inline int vm_need_tpr_shadow(struct kvm
*kvm)
        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;
@@ -916,6 +940,7 @@ static __init int setup_vmcs_config(struct
vmcs_config *vmcs_conf)
        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;
 
@@ -933,11 +958,8 @@ static __init int setup_vmcs_config(struct
vmcs_config *vmcs_conf)
              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;
@@ -946,6 +968,18 @@ static __init int setup_vmcs_config(struct
vmcs_config *vmcs_conf)
                _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
@@ -983,6 +1017,7 @@ static __init int setup_vmcs_config(struct
vmcs_config *vmcs_conf)
 
        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;
 
@@ -1425,6 +1460,26 @@ static void seg_setup(int seg)
        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;
+
+       r = -EFAULT;
+       /* Top memslot for apic access page */
+       if (kvm->nmemslots == KVM_MEMORY_SLOTS)
+               return r;
+       kvm_userspace_mem.slot = kvm->nmemslots + 1;
+       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)
+               return r;
+       kvm->apic_access_page = gfn_to_page(kvm, 0xfee00);
+       return 0;
+}
+
 /*
  * Sets up the vmcs for emulated real mode.
  */
@@ -1456,8 +1511,14 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
                                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 */
@@ -1526,6 +1587,10 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
        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;
 }
 
@@ -1614,13 +1679,17 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)
 
        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 */
@@ -2119,6 +2188,26 @@ static int handle_vmcall(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run)
        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
@@ -2138,7 +2227,8 @@ static int (*kvm_vmx_exit_handlers[])(struct
kvm_vcpu *vcpu,
        [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..11d7341 100644
--- a/drivers/kvm/vmx.h
+++ b/drivers/kvm/vmx.h
@@ -89,6 +89,8 @@ enum vmcs_field {
        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 @@ enum vmcs_field {
 #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
-- 
1.5.2

Attachment: 0002-KVM-VMX-Enable-memory-mapped-TPR-shadow-FlexPriori.patch
Description: 0002-KVM-VMX-Enable-memory-mapped-TPR-shadow-FlexPriori.patch

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