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Diffstat (limited to 'arch/x86/kvm/svm.c')
-rw-r--r--arch/x86/kvm/svm.c25
1 files changed, 17 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 91000501756e..50d1ebafe0b3 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1933,14 +1933,6 @@ static void sev_clflush_pages(struct page *pages[], unsigned long npages)
static void __unregister_enc_region_locked(struct kvm *kvm,
struct enc_region *region)
{
- /*
- * The guest may change the memory encryption attribute from C=0 -> C=1
- * or vice versa for this memory range. Lets make sure caches are
- * flushed to ensure that guest data gets written into memory with
- * correct C-bit.
- */
- sev_clflush_pages(region->pages, region->npages);
-
sev_unpin_memory(kvm, region->pages, region->npages);
list_del(&region->list);
kfree(region);
@@ -1971,6 +1963,13 @@ static void sev_vm_destroy(struct kvm *kvm)
mutex_lock(&kvm->lock);
/*
+ * Ensure that all guest tagged cache entries are flushed before
+ * releasing the pages back to the system for use. CLFLUSH will
+ * not do this, so issue a WBINVD.
+ */
+ wbinvd_on_all_cpus();
+
+ /*
* if userspace was terminated before unregistering the memory regions
* then lets unpin all the registered memory.
*/
@@ -7158,6 +7157,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
if (!svm_sev_enabled())
return -ENOTTY;
+ if (!argp)
+ return 0;
+
if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
return -EFAULT;
@@ -7285,6 +7287,13 @@ static int svm_unregister_enc_region(struct kvm *kvm,
goto failed;
}
+ /*
+ * Ensure that all guest tagged cache entries are flushed before
+ * releasing the pages back to the system for use. CLFLUSH will
+ * not do this, so issue a WBINVD.
+ */
+ wbinvd_on_all_cpus();
+
__unregister_enc_region_locked(kvm, region);
mutex_unlock(&kvm->lock);