KVM: SVM: Implement hsave
Implement the hsave MSR, that gives the VCPU a GPA to save the
old guest state in.
v2 allows userspace to save/restore hsave
v4 dummys out the hsave MSR, so we use a host page
v6 remembers the guest's hsave and exports the MSR
Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 79cc06b..59aaff1 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -626,6 +626,7 @@
struct vcpu_svm *svm;
struct page *page;
struct page *msrpm_pages;
+ struct page *hsave_page;
int err;
svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
@@ -651,6 +652,11 @@
svm->msrpm = page_address(msrpm_pages);
svm_vcpu_init_msrpm(svm->msrpm);
+ hsave_page = alloc_page(GFP_KERNEL);
+ if (!hsave_page)
+ goto uninit;
+ svm->hsave = page_address(hsave_page);
+
svm->vmcb = page_address(page);
clear_page(svm->vmcb);
svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
@@ -680,6 +686,7 @@
__free_page(pfn_to_page(svm->vmcb_pa >> PAGE_SHIFT));
__free_pages(virt_to_page(svm->msrpm), MSRPM_ALLOC_ORDER);
+ __free_page(virt_to_page(svm->hsave));
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, svm);
}
@@ -1377,6 +1384,9 @@
case MSR_IA32_LASTINTTOIP:
*data = svm->vmcb->save.last_excp_to;
break;
+ case MSR_VM_HSAVE_PA:
+ *data = svm->hsave_msr;
+ break;
default:
return kvm_get_msr_common(vcpu, ecx, data);
}
@@ -1471,6 +1481,9 @@
pr_unimpl(vcpu, "unimplemented perfctr wrmsr: 0x%x data 0x%llx\n", ecx, data);
break;
+ case MSR_VM_HSAVE_PA:
+ svm->hsave_msr = data;
+ break;
default:
return kvm_set_msr_common(vcpu, ecx, data);
}