Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/kvm/svm/sev.c | 117 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 112 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index f640b8beb443e..eb95914578497 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -15,6 +15,7 @@
#include <linux/pagemap.h>
#include <linux/swap.h>
+#include "mmu.h"
#include "x86.h"
#include "svm.h"
@@ -415,6 +416,107 @@ static unsigned long get_num_contig_pages(unsigned long
idx,
return pages;
}
+#define SEV_PFERR (PFERR_WRITE_MASK | PFERR_USER_MASK)
+
+static void *sev_alloc_pages(unsigned long size, unsigned long *npages)
+{
+ /* TODO */
+ *npages = 0;
+ return NULL;
+}
+
+static struct kvm_memory_slot *hva_to_memslot(struct kvm *kvm,
+ unsigned long hva)
+{
+ struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memory_slot *memslot;
+
+ kvm_for_each_memslot(memslot, slots) {
+ if (hva >= memslot->userspace_addr &&
+ hva < memslot->userspace_addr +
+ (memslot->npages << PAGE_SHIFT))
+ return memslot;
+ }
+
+ return NULL;
+}
+
+static bool hva_to_gpa(struct kvm *kvm, unsigned long hva)
+{
+ struct kvm_memory_slot *memslot;
+ gpa_t gpa_offset;
+
+ memslot = hva_to_memslot(kvm, hva);
+ if (!memslot)
+ return UNMAPPED_GVA;
+
+ gpa_offset = hva - memslot->userspace_addr;
+ return ((memslot->base_gfn << PAGE_SHIFT) + gpa_offset);
+}
+
+static struct page **sev_pin_memory_in_mmu(struct kvm *kvm, unsigned long addr,
+ unsigned long size,
+ unsigned long *npages)
+{
+ struct kvm_vcpu *vcpu;
+ struct page **pages;
+ unsigned long i;
+ kvm_pfn_t pfn;
+ int idx, ret;
+ gpa_t gpa;
+
+ pages = sev_alloc_pages(size, npages);
+ if (!pages)
+ return ERR_PTR(-ENOMEM);
+
+ vcpu = kvm_get_vcpu(kvm, 0);
+ if (mutex_lock_killable(&vcpu->mutex)) {
+ kvfree(pages);
+ return ERR_PTR(-EINTR);
+ }
+
+ vcpu_load(vcpu);
+ idx = srcu_read_lock(&kvm->srcu);
+
+ kvm_mmu_load(vcpu);
+
+ for (i = 0; i < *npages; i++, addr += PAGE_SIZE) {
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ goto err;
+ }
+
+ if (need_resched())
+ cond_resched();
+
+ gpa = hva_to_gpa(kvm, addr);
+ if (gpa == UNMAPPED_GVA) {
+ ret = -EFAULT;
+ goto err;
+ }
+ pfn = kvm_mmu_map_tdp_page(vcpu, gpa, SEV_PFERR, PG_LEVEL_4K);
+ if (is_error_noslot_pfn(pfn)) {
+ ret = -EFAULT;
+ goto err;
+ }
+ pages[i] = pfn_to_page(pfn);
+ get_page(pages[i]);
+ }
+
+ srcu_read_unlock(&kvm->srcu, idx);
+ vcpu_put(vcpu);
+
+ mutex_unlock(&vcpu->mutex);
+ return pages;
+
+err:
+ for ( ; i; --i)
+ put_page(pages[i-1]);
+
+ kvfree(pages);
+ return ERR_PTR(ret);
+}
+
static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
{
unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
@@ -439,9 +541,12 @@ static int sev_launch_update_data(struct kvm *kvm, struct
kvm_sev_cmd *argp)
vaddr_end = vaddr + size;
/* Lock the user memory. */
- inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
- if (!inpages) {
- ret = -ENOMEM;
+ if (atomic_read(&kvm->online_vcpus))
+ inpages = sev_pin_memory_in_mmu(kvm, vaddr, size, &npages);
+ else
+ inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);
+ if (IS_ERR(inpages)) {
+ ret = PTR_ERR(inpages);
goto e_free;
}
@@ -449,9 +554,11 @@ static int sev_launch_update_data(struct kvm *kvm, struct
kvm_sev_cmd *argp)
* The LAUNCH_UPDATE 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.
+ * unencrypted so invalidate it first. Flushing is automatically
+ * handled if the pages can be pinned in the MMU.
*/
- sev_clflush_pages(inpages, npages);
+ if (!atomic_read(&kvm->online_vcpus))
+ sev_clflush_pages(inpages, npages);
for (i = 0; vaddr < vaddr_end; vaddr = next_vaddr, i += pages) {
int offset, len;
--
2.28.0
