[PATCH 2/3] KVM: SVM: allocate the MSR permission map per VCPU

Joerg Roedel
2008-02-12T15:27:09Z

This patch changes the kvm-amd module to allocate the SVM MSR permission map
per VCPU instead of a global map for all VCPUs. With this we have more
flexibility allowing specific guests to access virtualized MSRs. This is
required for LBRV virtualization.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Markus Rechberger <markus.rechberger@amd.com>
---
arch/x86/kvm/kvm_svm.h | 2 +
arch/x86/kvm/svm.c | 67 +++++++++++++++++++++++-------------------------
2 files changed, 34 insertions(+), 35 deletions(-)

diff --git a/arch/x86/kvm/kvm_svm.h b/arch/x86/kvm/kvm_svm.h
index ecdfe97..65ef0fc 100644
--- a/arch/x86/kvm/kvm_svm.h
+++ b/arch/x86/kvm/kvm_svm.h
@@ -39,6 +39,8 @@ struct vcpu_svm {
unsigned long host_db_regs[NUM_DB_REGS];
unsigned long host_dr6;
unsigned long host_dr7;
+
+ u32 *msrpm;
};

#endif
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6e0c6bd..50ee223 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -65,7 +65,6 @@ static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
}

unsigned long iopm_base;
-unsigned long msrpm_base;

struct kvm_ldttss_desc {
u16 limit0;
@@ -370,12 +369,29 @@ static void set_msr_interception(u32 *msrpm, unsigned msr,
BUG();
}

+static void svm_vcpu_init_msrpm(u32 *msrpm)
+{
+ memset(msrpm, 0xff, PAGE_SIZE * (1 << MSRPM_ALLOC_ORDER));
+
+#ifdef CONFIG_X86_64
+ set_msr_interception(msrpm, MSR_GS_BASE, 1, 1);
+ set_msr_interception(msrpm, MSR_FS_BASE, 1, 1);
+ set_msr_interception(msrpm, MSR_KERNEL_GS_BASE, 1, 1);
+ set_msr_interception(msrpm, MSR_LSTAR, 1, 1);
+ set_msr_interception(msrpm, MSR_CSTAR, 1, 1);
+ set_msr_interception(msrpm, MSR_SYSCALL_MASK, 1, 1);
+#endif
+ set_msr_interception(msrpm, MSR_K6_STAR, 1, 1);
+ set_msr_interception(msrpm, MSR_IA32_SYSENTER_CS, 1, 1);
+ set_msr_interception(msrpm, MSR_IA32_SYSENTER_ESP, 1, 1);
+ set_msr_interception(msrpm, MSR_IA32_SYSENTER_EIP, 1, 1);
+}
+
static __init int svm_hardware_setup(void)
{
int cpu;
struct page *iopm_pages;
- struct page *msrpm_pages;
- void *iopm_va, *msrpm_va;
+ void *iopm_va;
int r;

iopm_pages = alloc_pages(GFP_KERNEL, IOPM_ALLOC_ORDER);
@@ -388,37 +404,13 @@ static __init int svm_hardware_setup(void)
clear_bit(0x80, iopm_va); /* allow direct access to PC debug port */
iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;

-
- msrpm_pages = alloc_pages(GFP_KERNEL, MSRPM_ALLOC_ORDER);
-
- r = -ENOMEM;
- if (!msrpm_pages)
- goto err_1;
-
- msrpm_va = page_address(msrpm_pages);
- memset(msrpm_va, 0xff, PAGE_SIZE * (1 << MSRPM_ALLOC_ORDER));
- msrpm_base = page_to_pfn(msrpm_pages) << PAGE_SHIFT;
-
-#ifdef CONFIG_X86_64
- set_msr_interception(msrpm_va, MSR_GS_BASE, 1, 1);
- set_msr_interception(msrpm_va, MSR_FS_BASE, 1, 1);
- set_msr_interception(msrpm_va, MSR_KERNEL_GS_BASE, 1, 1);
- set_msr_interception(msrpm_va, MSR_LSTAR, 1, 1);
- set_msr_interception(msrpm_va, MSR_CSTAR, 1, 1);
- set_msr_interception(msrpm_va, MSR_SYSCALL_MASK, 1, 1);
-#endif
- set_msr_interception(msrpm_va, MSR_K6_STAR, 1, 1);
- set_msr_interception(msrpm_va, MSR_IA32_SYSENTER_CS, 1, 1);
- set_msr_interception(msrpm_va, MSR_IA32_SYSENTER_ESP, 1, 1);
- set_msr_interception(msrpm_va, MSR_IA32_SYSENTER_EIP, 1, 1);
-
if (boot_cpu_has(X86_FEATURE_NX))
kvm_enable_efer_bits(EFER_NX);

for_each_online_cpu(cpu) {
r = svm_cpu_init(cpu);
if (r)
- goto err_2;
+ goto err;
}

svm_features = cpuid_edx(SVM_CPUID_FUNC);
@@ -438,10 +430,7 @@ static __init int svm_hardware_setup(void)

return 0;

-err_2:
- __free_pages(msrpm_pages, MSRPM_ALLOC_ORDER);
- msrpm_base = 0;
-err_1:
+err:
__free_pages(iopm_pages, IOPM_ALLOC_ORDER);
iopm_base = 0;
return r;
@@ -449,9 +438,8 @@ err_1:

static __exit void svm_hardware_unsetup(void)
{
- __free_pages(pfn_to_page(msrpm_base >> PAGE_SHIFT), MSRPM_ALLOC_ORDER);
__free_pages(pfn_to_page(iopm_base >> PAGE_SHIFT), IOPM_ALLOC_ORDER);
- iopm_base = msrpm_base = 0;
+ iopm_base = 0;
}

static void init_seg(struct vmcb_seg *seg)
@@ -536,7 +524,7 @@ static void init_vmcb(struct vcpu_svm *svm)
(1ULL << INTERCEPT_MWAIT);

control->iopm_base_pa = iopm_base;
- control->msrpm_base_pa = msrpm_base;
+ control->msrpm_base_pa = __pa(svm->msrpm);
control->tsc_offset = 0;
control->int_ctl = V_INTR_MASKING_MASK;

@@ -615,6 +603,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
{
struct vcpu_svm *svm;
struct page *page;
+ struct page *msrpm_pages;
int err;

svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
@@ -633,6 +622,13 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
goto uninit;
}

+ err = -ENOMEM;
+ msrpm_pages = alloc_pages(GFP_KERNEL, MSRPM_ALLOC_ORDER);
+ if (!msrpm_pages)
+ goto uninit;
+ svm->msrpm = page_address(msrpm_pages);
+ svm_vcpu_init_msrpm(svm->msrpm);
+
svm->vmcb = page_address(page);
clear_page(svm->vmcb);
svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
@@ -661,6 +657,7 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
struct vcpu_svm *svm = to_svm(vcpu);

__free_page(pfn_to_page(svm->vmcb_pa >> PAGE_SHIFT));
+ __free_pages(virt_to_page(svm->msrpm), MSRPM_ALLOC_ORDER);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, svm);
}
--
1.5.3.7