[PATCH] KVM: VMX: Allocate MSR Bitmap for each vcpu

[Sheng Yang <sheng.yang@intel.com>]

Separate msr_bitmap for each vcpu, prepared for guest PAT support.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
---
 arch/x86/kvm/vmx.c |   53 +++++++++++++++++++++++++++++----------------------
 1 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 14671f4..7f53fb7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -90,6 +90,7 @@ struct vcpu_vmx {
 	} rmode;
 	int vpid;
 	bool emulation_required;
+	struct page *msr_bitmap;
 };
 
 static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu)
@@ -106,7 +107,6 @@ static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu);
 
 static struct page *vmx_io_bitmap_a;
 static struct page *vmx_io_bitmap_b;
-static struct page *vmx_msr_bitmap;
 
 static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
 static DEFINE_SPINLOCK(vmx_vpid_lock);
@@ -2083,6 +2083,25 @@ static void vmx_disable_intercept_for_msr(struct page *msr_bitmap, u32 msr)
 	kunmap(msr_bitmap);
 }
 
+static int setup_msr_bitmap(struct page *msr_bitmap)
+{
+	void *va;
+
+	va = kmap(msr_bitmap);
+	if (!va)
+		return -EINVAL;
+	memset(va, 0xff, PAGE_SIZE);
+	kunmap(msr_bitmap);
+
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_FS_BASE);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_GS_BASE);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP);
+	vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP);
+
+	return 0;
+}
+
 /*
  * Sets up the vmcs for emulated real mode.
  */
@@ -2100,8 +2119,10 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
 	vmcs_write64(IO_BITMAP_A, page_to_phys(vmx_io_bitmap_a));
 	vmcs_write64(IO_BITMAP_B, page_to_phys(vmx_io_bitmap_b));
 
-	if (cpu_has_vmx_msr_bitmap())
-		vmcs_write64(MSR_BITMAP, page_to_phys(vmx_msr_bitmap));
+	if (cpu_has_vmx_msr_bitmap()) {
+		setup_msr_bitmap(vmx->msr_bitmap);
+		vmcs_write64(MSR_BITMAP, page_to_phys(vmx->msr_bitmap));
+	}
 
 	vmcs_write64(VMCS_LINK_POINTER, -1ull); /* 22.3.1.5 */
 
@@ -3362,6 +3383,7 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
 	vmx_free_vmcs(vcpu);
 	kfree(vmx->host_msrs);
 	kfree(vmx->guest_msrs);
+	__free_page(vmx->msr_bitmap);
 	kvm_vcpu_uninit(vcpu);
 	kmem_cache_free(kvm_vcpu_cache, vmx);
 }
@@ -3397,6 +3419,10 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 
 	vmcs_clear(vmx->vmcs);
 
+	vmx->msr_bitmap = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+	if (!vmx->msr_bitmap)
+		goto free_vmcs;
+
 	cpu = get_cpu();
 	vmx_vcpu_load(&vmx->vcpu, cpu);
 	err = vmx_vcpu_setup(vmx);
@@ -3518,12 +3544,6 @@ static int __init vmx_init(void)
 		goto out;
 	}
 
-	vmx_msr_bitmap = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
-	if (!vmx_msr_bitmap) {
-		r = -ENOMEM;
-		goto out1;
-	}
-
 	/*
 	 * Allow direct access to the PC debug port (it is often used for I/O
 	 * delays, but the vmexits simply slow things down).
@@ -3537,21 +3557,11 @@ static int __init vmx_init(void)
 	memset(va, 0xff, PAGE_SIZE);
 	kunmap(vmx_io_bitmap_b);
 
-	va = kmap(vmx_msr_bitmap);
-	memset(va, 0xff, PAGE_SIZE);
-	kunmap(vmx_msr_bitmap);
-
 	set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */
 
 	r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx), THIS_MODULE);
 	if (r)
-		goto out2;
-
-	vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_FS_BASE);
-	vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_GS_BASE);
-	vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_IA32_SYSENTER_CS);
-	vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_IA32_SYSENTER_ESP);
-	vmx_disable_intercept_for_msr(vmx_msr_bitmap, MSR_IA32_SYSENTER_EIP);
+		goto out1;
 
 	if (vm_need_ept()) {
 		bypass_guest_pf = 0;
@@ -3572,8 +3582,6 @@ static int __init vmx_init(void)
 
 	return 0;
 
-out2:
-	__free_page(vmx_msr_bitmap);
 out1:
 	__free_page(vmx_io_bitmap_b);
 out:
@@ -3583,7 +3591,6 @@ out:
 
 static void __exit vmx_exit(void)
 {
-	__free_page(vmx_msr_bitmap);
 	__free_page(vmx_io_bitmap_b);
 	__free_page(vmx_io_bitmap_a);
 
-- 
1.5.4.5