| Message ID | 20200808003746.66687-1-cfir@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] KVM: SVM: Mark SEV launch secret pages as dirty. | expand |
On 8/7/20 7:37 PM, Cfir Cohen wrote: > The LAUNCH_SECRET command performs encryption of the > launch secret memory contents. Mark pinned pages as > dirty, before unpinning them. > This matches the logic in sev_launch_update_data(). > > Signed-off-by: Cfir Cohen <cfir@google.com> > --- > Changelog since v1: > - Updated commit message. > > arch/x86/kvm/svm/sev.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) Reviewed-by: Brijesh Singh <brijesh.singh@amd.com> > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 5573a97f1520..37c47d26b9f7 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -850,7 +850,7 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) > struct kvm_sev_launch_secret params; > struct page **pages; > void *blob, *hdr; > - unsigned long n; > + unsigned long n, i; > int ret, offset; > > if (!sev_guest(kvm)) > @@ -863,6 +863,14 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) > if (!pages) > return -ENOMEM; > > + /* > + * The LAUNCH_SECRET command will perform in-place encryption of the > + * memory content (i.e it will write the same memory region with C=1). > + * It's possible that the cache may contain the data with C=0, i.e., > + * unencrypted so invalidate it first. > + */ > + sev_clflush_pages(pages, n); > + > /* > * The secret must be copied into contiguous memory region, lets verify > * that userspace memory pages are contiguous before we issue command. > @@ -908,6 +916,11 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) > e_free: > kfree(data); > e_unpin_memory: > + /* content of memory is updated, mark pages dirty */ > + for (i = 0; i < n; i++) { > + set_page_dirty_lock(pages[i]); > + mark_page_accessed(pages[i]); > + } > sev_unpin_memory(kvm, pages, n); > return ret; > }
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 5573a97f1520..37c47d26b9f7 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -850,7 +850,7 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) struct kvm_sev_launch_secret params; struct page **pages; void *blob, *hdr; - unsigned long n; + unsigned long n, i; int ret, offset; if (!sev_guest(kvm)) @@ -863,6 +863,14 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) if (!pages) return -ENOMEM; + /* + * The LAUNCH_SECRET command will perform in-place encryption of the + * memory content (i.e it will write the same memory region with C=1). + * It's possible that the cache may contain the data with C=0, i.e., + * unencrypted so invalidate it first. + */ + sev_clflush_pages(pages, n); + /* * The secret must be copied into contiguous memory region, lets verify * that userspace memory pages are contiguous before we issue command. @@ -908,6 +916,11 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) e_free: kfree(data); e_unpin_memory: + /* content of memory is updated, mark pages dirty */ + for (i = 0; i < n; i++) { + set_page_dirty_lock(pages[i]); + mark_page_accessed(pages[i]); + } sev_unpin_memory(kvm, pages, n); return ret; }
The LAUNCH_SECRET command performs encryption of the launch secret memory contents. Mark pinned pages as dirty, before unpinning them. This matches the logic in sev_launch_update_data(). Signed-off-by: Cfir Cohen <cfir@google.com> --- Changelog since v1: - Updated commit message. arch/x86/kvm/svm/sev.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)