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[6/8] KVM: selftests: Add additional pages to the guest to accommodate ucall

Message ID 20230301053425.3880773-7-aaronlewis@google.com (mailing list archive)
State New, archived
Headers show
Series Add printf and formatted asserts in the guest | expand

Commit Message

Aaron Lewis March 1, 2023, 5:34 a.m. UTC
Add additional pages to the guest to account for the number of pages
the ucall framework uses.

This is done in preparation for adding string formatting options to
the guest through ucall helpers.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
---
 tools/testing/selftests/kvm/include/ucall_common.h | 1 +
 tools/testing/selftests/kvm/lib/kvm_util.c         | 4 ++++
 tools/testing/selftests/kvm/lib/ucall_common.c     | 5 +++++
 3 files changed, 10 insertions(+)

Comments

Sean Christopherson March 23, 2023, 10:07 p.m. UTC | #1
On Wed, Mar 01, 2023, Aaron Lewis wrote:
> Add additional pages to the guest to account for the number of pages
> the ucall framework uses.
> 
> This is done in preparation for adding string formatting options to
> the guest through ucall helpers.
> 
> Signed-off-by: Aaron Lewis <aaronlewis@google.com>
> ---
>  tools/testing/selftests/kvm/include/ucall_common.h | 1 +
>  tools/testing/selftests/kvm/lib/kvm_util.c         | 4 ++++
>  tools/testing/selftests/kvm/lib/ucall_common.c     | 5 +++++
>  3 files changed, 10 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h
> index 1a6aaef5ccae..0b1fde23729b 100644
> --- a/tools/testing/selftests/kvm/include/ucall_common.h
> +++ b/tools/testing/selftests/kvm/include/ucall_common.h
> @@ -34,6 +34,7 @@ void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu);
>  void ucall(uint64_t cmd, int nargs, ...);
>  uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc);
>  void ucall_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa);
> +int ucall_header_size(void);

I like keeping the ucall_header definition in ucall_common.c, but we should hide
away the detail that it's a "header" (which doesn't even really make sense to me).

E.g. maybe ucall_nr_pages_required()?  And then obviously do the align_up() and
whatnot in the helper.
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h
index 1a6aaef5ccae..0b1fde23729b 100644
--- a/tools/testing/selftests/kvm/include/ucall_common.h
+++ b/tools/testing/selftests/kvm/include/ucall_common.h
@@ -34,6 +34,7 @@  void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu);
 void ucall(uint64_t cmd, int nargs, ...);
 uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc);
 void ucall_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa);
+int ucall_header_size(void);
 
 /*
  * Perform userspace call without any associated data.  This bare call avoids
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 3ea24a5f4c43..e1d6a2f40d2d 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -307,6 +307,7 @@  static uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
 				     uint32_t nr_runnable_vcpus,
 				     uint64_t extra_mem_pages)
 {
+	uint64_t page_size = vm_guest_mode_params[mode].page_size;
 	uint64_t nr_pages;
 
 	TEST_ASSERT(nr_runnable_vcpus,
@@ -335,6 +336,9 @@  static uint64_t vm_nr_pages_required(enum vm_guest_mode mode,
 	 */
 	nr_pages += (nr_pages + extra_mem_pages) / PTES_PER_MIN_PAGE * 2;
 
+	/* Account for the number of pages needed by ucall. */
+	nr_pages += align_up(ucall_header_size(), page_size) / page_size;
+
 	return vm_adjust_num_guest_pages(mode, nr_pages);
 }
 
diff --git a/tools/testing/selftests/kvm/lib/ucall_common.c b/tools/testing/selftests/kvm/lib/ucall_common.c
index 2f0e2ea941cc..b6a75858fe0d 100644
--- a/tools/testing/selftests/kvm/lib/ucall_common.c
+++ b/tools/testing/selftests/kvm/lib/ucall_common.c
@@ -11,6 +11,11 @@  struct ucall_header {
 	struct ucall ucalls[KVM_MAX_VCPUS];
 };
 
+int ucall_header_size(void)
+{
+	return sizeof(struct ucall_header);
+}
+
 /*
  * ucall_pool holds per-VM values (global data is duplicated by each VM), it
  * must not be accessed from host code.