Re: [PATCH v14 00/34] KVM: guest_memfd() and per-page attributes

From: Paolo Bonzini
Date: Mon Nov 13 2023 - 07:22:18 EST

On 11/5/23 17:30, Paolo Bonzini wrote:
The "development cycle" for this version is going to be very short;
ideally, next week I will merge it as is in kvm/next, taking this through
the KVM tree for 6.8 immediately after the end of the merge window.
The series is still based on 6.6 (plus KVM changes for 6.7) so it
will require a small fixup for changes to get_file_rcu() introduced in
6.7 by commit 0ede61d8589c ("file: convert to SLAB_TYPESAFE_BY_RCU").
The fixup will be done as part of the merge commit, and most of the text
above will become the commit message for the merge.

The changes from review are small enough and entirely in tests, so
I went ahead and pushed it to kvm/next, together with "selftests: kvm/s390x: use vm_create_barebones()" which also fixed testcase failures (similar to the aarch64/page_fault_test.c hunk below).

The guestmemfd branch on kvm.git was force-pushed, and can be used for further
development if you don't want to run 6.7-rc1 for whatever reason.

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 38882263278d..926241e23aeb 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -1359,7 +1359,6 @@ yet and must be cleared on entry.
__u64 guest_phys_addr;
__u64 memory_size; /* bytes */
__u64 userspace_addr; /* start of the userspace allocated memory */
- __u64 pad[16];
};
/* for kvm_userspace_memory_region::flags */
diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index eb4217b7c768..08a5ca5bed56 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -705,7 +705,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
print_test_banner(mode, p);
- vm = ____vm_create(mode);
+ vm = ____vm_create(VM_SHAPE(mode));
setup_memslots(vm, p);
kvm_vm_elf_load(vm, program_invocation_name);
setup_ucall(vm);
diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index ea0ae7e25330..fd389663c49b 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -6,14 +6,6 @@
*/
#define _GNU_SOURCE
-#include "test_util.h"
-#include "kvm_util_base.h"
-#include <linux/bitmap.h>
-#include <linux/falloc.h>
-#include <sys/mman.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
@@ -21,6 +13,15 @@
#include <stdio.h>
#include <fcntl.h>
+#include <linux/bitmap.h>
+#include <linux/falloc.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "test_util.h"
+#include "kvm_util_base.h"
+
static void test_file_read_write(int fd)
{
char buf[64];
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index e4d2cd9218b2..1b58f943562f 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -819,6 +819,7 @@ static inline struct kvm_vm *vm_create_barebones(void)
return ____vm_create(VM_SHAPE_DEFAULT);
}
+#ifdef __x86_64__
static inline struct kvm_vm *vm_create_barebones_protected_vm(void)
{
const struct vm_shape shape = {
@@ -828,6 +829,7 @@ static inline struct kvm_vm *vm_create_barebones_protected_vm(void)
return ____vm_create(shape);
}
+#endif
static inline struct kvm_vm *vm_create(uint32_t nr_runnable_vcpus)
{
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index d05d95cc3693..9b29cbf49476 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1214,7 +1214,7 @@ void vm_guest_mem_fallocate(struct kvm_vm *vm, uint64_t base, uint64_t size,
TEST_ASSERT(region && region->region.flags & KVM_MEM_GUEST_MEMFD,
"Private memory region not found for GPA 0x%lx", gpa);
- offset = (gpa - region->region.guest_phys_addr);
+ offset = gpa - region->region.guest_phys_addr;
fd_offset = region->region.guest_memfd_offset + offset;
len = min_t(uint64_t, end - gpa, region->region.memory_size - offset);
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
index 343e807043e1..1efee1cfcff0 100644
--- a/tools/testing/selftests/kvm/set_memory_region_test.c
+++ b/tools/testing/selftests/kvm/set_memory_region_test.c
@@ -433,6 +433,7 @@ static void test_add_max_memory_regions(void)
}
+#ifdef __x86_64__
static void test_invalid_guest_memfd(struct kvm_vm *vm, int memfd,
size_t offset, const char *msg)
{
@@ -523,14 +524,13 @@ static void test_add_overlapping_private_memory_regions(void)
close(memfd);
kvm_vm_free(vm);
}
+#endif
int main(int argc, char *argv[])
{
#ifdef __x86_64__
int i, loops;
-#endif
-#ifdef __x86_64__
/*
* FIXME: the zero-memslot test fails on aarch64 and s390x because
* KVM_RUN fails with ENOEXEC or EFAULT.
@@ -542,6 +542,7 @@ int main(int argc, char *argv[])
test_add_max_memory_regions();
+#ifdef __x86_64__
if (kvm_has_cap(KVM_CAP_GUEST_MEMFD) &&
(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM))) {
test_add_private_memory_region();
@@ -550,7 +551,6 @@ int main(int argc, char *argv[])
pr_info("Skipping tests for KVM_MEM_GUEST_MEMFD memory regions\n");
}
-#ifdef __x86_64__
if (argc > 1)
loops = atoi_positive("Number of iterations", argv[1]);
else
diff --git a/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c b/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c
index 2f02f6128482..13e72fcec8dd 100644
--- a/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c
+++ b/tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Copyright (C) 2022, Google LLC.
+ * Copyright (C) 2023, Google LLC.
*/
#include <linux/kvm.h>
#include <pthread.h>

Paolo