KVM: SVM: Define actual size of IOPM and MSRPM tables

Define the actual size of the IOPM and MSRPM tables so that the actual size
can be used when initializing them and when checking the consistency of their
physical address.
These #defines are placed in svm.h so that they can be shared.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <20210412215611.110095-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/svm.c

@@ -56,9 +56,6 @@ static const struct x86_cpu_id svm_cpu_id[] = {
 MODULE_DEVICE_TABLE(x86cpu, svm_cpu_id);
 #endif
 
-#define IOPM_ALLOC_ORDER 2
-#define MSRPM_ALLOC_ORDER 1
-
 #define SEG_TYPE_LDT 2
 #define SEG_TYPE_BUSY_TSS16 3
 
@@ -683,14 +680,15 @@ void set_msr_interception(struct kvm_vcpu *vcpu, u32 *msrpm, u32 msr,
 
 u32 *svm_vcpu_alloc_msrpm(void)
 {
-	struct page *pages = alloc_pages(GFP_KERNEL_ACCOUNT, MSRPM_ALLOC_ORDER);
+	unsigned int order = get_order(MSRPM_SIZE);
+	struct page *pages = alloc_pages(GFP_KERNEL_ACCOUNT, order);
 	u32 *msrpm;
 
 	if (!pages)
 		return NULL;
 
 	msrpm = page_address(pages);
-	memset(msrpm, 0xff, PAGE_SIZE * (1 << MSRPM_ALLOC_ORDER));
+	memset(msrpm, 0xff, PAGE_SIZE * (1 << order));
 
 	return msrpm;
 }
@@ -709,7 +707,7 @@ void svm_vcpu_init_msrpm(struct kvm_vcpu *vcpu, u32 *msrpm)
 
 void svm_vcpu_free_msrpm(u32 *msrpm)
 {
-	__free_pages(virt_to_page(msrpm), MSRPM_ALLOC_ORDER);
+	__free_pages(virt_to_page(msrpm), get_order(MSRPM_SIZE));
 }
 
 static void svm_msr_filter_changed(struct kvm_vcpu *vcpu)
@@ -896,7 +894,8 @@ static void svm_hardware_teardown(void)
 	for_each_possible_cpu(cpu)
 		svm_cpu_uninit(cpu);
 
-	__free_pages(pfn_to_page(iopm_base >> PAGE_SHIFT), IOPM_ALLOC_ORDER);
+	__free_pages(pfn_to_page(iopm_base >> PAGE_SHIFT),
+	get_order(IOPM_SIZE));
 	iopm_base = 0;
 }
 
@@ -932,14 +931,15 @@ static __init int svm_hardware_setup(void)
 	struct page *iopm_pages;
 	void *iopm_va;
 	int r;
+	unsigned int order = get_order(IOPM_SIZE);
 
-	iopm_pages = alloc_pages(GFP_KERNEL, IOPM_ALLOC_ORDER);
+	iopm_pages = alloc_pages(GFP_KERNEL, order);
 
 	if (!iopm_pages)
 		return -ENOMEM;
 
 	iopm_va = page_address(iopm_pages);
-	memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER));
+	memset(iopm_va, 0xff, PAGE_SIZE * (1 << order));
 	iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;
 
 	init_msrpm_offsets();
@@ -1416,7 +1416,7 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
 	sev_free_vcpu(vcpu);
 
 	__free_page(pfn_to_page(__sme_clr(svm->vmcb01.pa) >> PAGE_SHIFT));
-	__free_pages(virt_to_page(svm->msrpm), MSRPM_ALLOC_ORDER);
+	__free_pages(virt_to_page(svm->msrpm), get_order(MSRPM_SIZE));
 }
 
 static void svm_prepare_guest_switch(struct kvm_vcpu *vcpu)

arch/x86/kvm/svm/svm.h

@@ -28,6 +28,9 @@ static const u32 host_save_user_msrs[] = {
 };
 #define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs)
 
+#define	IOPM_SIZE PAGE_SIZE * 3
+#define	MSRPM_SIZE PAGE_SIZE * 2
+
 #define MAX_DIRECT_ACCESS_MSRS	20
 #define MSRPM_OFFSETS	16
 extern u32 msrpm_offsets[MSRPM_OFFSETS] __read_mostly;