Add support for guest side functionality to modify encryption/shared
masks for entries in page table to allow accessing GPA ranges as private
or shared.
Signed-off-by: Vishal Annapurve <vannapurve@xxxxxxxxxx>
---
.../selftests/kvm/include/x86_64/processor.h | 4 ++
.../selftests/kvm/lib/x86_64/processor.c | 39 +++++++++++++++++++
2 files changed, 43 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 3617f83bb2e5..c8c55f54c14f 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -945,6 +945,10 @@ void vcpu_init_descriptor_tables(struct kvm_vcpu *vcpu);
void vm_install_exception_handler(struct kvm_vm *vm, int vector,
void (*handler)(struct ex_regs *));
+void guest_set_region_shared(void *vaddr, uint64_t size);
+
+void guest_set_region_private(void *vaddr, uint64_t size);
+
/* If a toddler were to say "abracadabra". */
#define KVM_EXCEPTION_MAGIC 0xabacadabaULL
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index ab7d4cc4b848..42d1e4074f32 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -276,6 +276,45 @@ static uint64_t *guest_code_get_pte(uint64_t vaddr)
return (uint64_t *)&pte[index[0]];
}
+static void guest_code_change_region_prot(void *vaddr_start, uint64_t mem_size,
+ bool private)
+{
+ uint64_t vaddr = (uint64_t)vaddr_start;
+ uint32_t num_pages;
+
+ GUEST_ASSERT(gpgt_info != NULL);
+ uint32_t guest_page_size = gpgt_info->page_size;
+
+ GUEST_ASSERT(!(mem_size % guest_page_size) && !(vaddr % guest_page_size));
+ GUEST_ASSERT(gpgt_info->enc_mask | gpgt_info->shared_mask);
+
+ num_pages = mem_size / guest_page_size;
+ for (uint32_t i = 0; i < num_pages; i++) {
+ uint64_t *pte = guest_code_get_pte(vaddr);
+
+ GUEST_ASSERT(pte);
+ if (private) {
+ *pte &= ~(gpgt_info->shared_mask);
+ *pte |= gpgt_info->enc_mask;
+ } else {
+ *pte &= ~(gpgt_info->enc_mask);
+ *pte |= gpgt_info->shared_mask;
+ }
+ asm volatile("invlpg (%0)" :: "r"(vaddr) : "memory");
+ vaddr += guest_page_size;
+ }
+}
+
+void guest_set_region_shared(void *vaddr, uint64_t size)
+{
+ guest_code_change_region_prot(vaddr, size, /* shared */ false);
+}
+
+void guest_set_region_private(void *vaddr, uint64_t size)
+{
+ guest_code_change_region_prot(vaddr, size, /* private */ true);
+}
+
void sync_vm_gpgt_info(struct kvm_vm *vm, vm_vaddr_t pgt_info)
{
gpgt_info = (struct guest_pgt_info *)pgt_info;
--
2.39.0.314.g84b9a713c41-goog
