[PATCH 2/6] Add arch specific additional guest pages

[Peter Gonda <pgonda@google.com>]

SEV-ES guests need additional pages allocated for their GHCBs. Add arch
specific function definition with __weak to allow for overriding for X86
specific SEV-ES functionality.

Cc: Vishal Annapurve <vannapurve@google.com>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Carlos Bilbao <carlos.bilbao@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: kvm@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Peter Gonda <pgonda@google.com>
---
 .../selftests/kvm/include/kvm_util_base.h        |  3 +++
 tools/testing/selftests/kvm/lib/kvm_util.c       | 16 ++++++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index 4a40b332115d..9a26afd2e82a 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -1126,4 +1126,7 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm);
 
 bool vm_is_gpa_protected(struct kvm_vm *vm, vm_paddr_t paddr);
 
+int kvm_arch_vm_additional_pages_required(struct vm_shape shape,
+					  uint64_t page_size);
+
 #endif /* SELFTEST_KVM_UTIL_BASE_H */
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index adc51b0712ca..2a7b2709eb8d 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -314,11 +314,11 @@ struct kvm_vm *____vm_create(struct vm_shape shape)
 	return vm;
 }
 
-static uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
+static uint64_t vm_nr_pages_required(struct vm_shape shape,
 				     uint32_t nr_runnable_vcpus,
 				     uint64_t extra_mem_pages)
 {
-	uint64_t page_size = vm_guest_mode_params[mode].page_size;
+	uint64_t page_size = vm_guest_mode_params[shape.mode].page_size;
 	uint64_t nr_pages;
 
 	TEST_ASSERT(nr_runnable_vcpus,
@@ -350,13 +350,15 @@ static uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
 	/* Account for the number of pages needed by ucall. */
 	nr_pages += ucall_nr_pages_required(page_size);
 
-	return vm_adjust_num_guest_pages(mode, nr_pages);
+	nr_pages += kvm_arch_vm_additional_pages_required(shape, page_size);
+
+	return vm_adjust_num_guest_pages(shape.mode, nr_pages);
 }
 
 struct kvm_vm *__vm_create(struct vm_shape shape, uint32_t nr_runnable_vcpus,
 			   uint64_t nr_extra_pages)
 {
-	uint64_t nr_pages = vm_nr_pages_required(shape.mode, nr_runnable_vcpus,
+	uint64_t nr_pages = vm_nr_pages_required(shape, nr_runnable_vcpus,
 						 nr_extra_pages);
 	struct userspace_mem_region *slot0;
 	struct kvm_vm *vm;
@@ -2246,6 +2248,12 @@ __weak void kvm_arch_vm_post_create(struct kvm_vm *vm)
 {
 }
 
+__weak int kvm_arch_vm_additional_pages_required(struct vm_shape shape,
+						 uint64_t page_size)
+{
+	return 0;
+}
+
 __weak void kvm_selftest_arch_init(void)
 {
 }
-- 
2.44.0.478.gd926399ef9-goog