[RFC PATCH 02/31] Add arch specific additional guest pages

[Neeraj Upadhyay]

From: Peter Gonda <pgonda@xxxxxxxxxx>

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@xxxxxxxxxx>
Cc: Ackerley Tng <ackerleytng@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Carlos Bilbao <carlos.bilbao@xxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Michael Roth <michael.roth@xxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@xxxxxxx>
---
 tools/testing/selftests/kvm/include/kvm_util.h |  2 ++
 tools/testing/selftests/kvm/lib/kvm_util.c     | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 4c4e5a847f67..b621a0f1907e 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -254,6 +254,8 @@ int get_kvm_param_integer(const char *param);
 int get_kvm_intel_param_integer(const char *param);
 int get_kvm_amd_param_integer(const char *param);
 
+int kvm_arch_vm_additional_pages_required(struct vm_shape shape,
+                                         uint64_t page_size);
 unsigned int kvm_check_cap(long cap);
 
 static inline bool kvm_has_cap(long cap)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 089488e2eaf6..18a44d8220ef 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -367,11 +367,11 @@ 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,
@@ -403,13 +403,15 @@ 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;
@@ -2247,6 +2249,12 @@ __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)
 {
 }
-- 
2.34.1