[PATCH 11/13] KVM: selftests: Refactor private mem conversions to prep for punch_hole test

Sean Christopherson
2023-09-21T21:02:45Z

Refactor the private memory conversions test to prepare for adding a test
to verify PUNCH_HOLE functionality *without* actually do a proper
conversion, i.e. without calling KVM_SET_MEMORY_ATTRIBUTES. Make setting
attributes optional, rename the guest code to be more descriptive, and
extract the ranges to a global variable (iterating over multiple ranges is
less interesting for PUNCH_HOLE, but with a common array it's trivially
easy to do so).

Fixes: 90535ca08f76 ("KVM: selftests: Add x86-only selftest for private memory conversions")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
.../kvm/x86_64/private_mem_conversions_test.c | 51 ++++++++++---------
1 file changed, 27 insertions(+), 24 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/private_mem_conversions_test.c b/tools/testing/selftests/kvm/x86_64/private_mem_conversions_test.c
index 50541246d6fd..b80cf7342d0d 100644
--- a/tools/testing/selftests/kvm/x86_64/private_mem_conversions_test.c
+++ b/tools/testing/selftests/kvm/x86_64/private_mem_conversions_test.c
@@ -83,13 +83,14 @@ static void guest_sync_private(uint64_t gpa, uint64_t size, uint8_t pattern)
}

/* Arbitrary values, KVM doesn't care about the attribute flags. */
-#define MAP_GPA_SHARED BIT(0)
-#define MAP_GPA_DO_FALLOCATE BIT(1)
+#define MAP_GPA_SET_ATTRIBUTES BIT(0)
+#define MAP_GPA_SHARED BIT(1)
+#define MAP_GPA_DO_FALLOCATE BIT(2)

static void guest_map_mem(uint64_t gpa, uint64_t size, bool map_shared,
bool do_fallocate)
{
- uint64_t flags = 0;
+ uint64_t flags = MAP_GPA_SET_ATTRIBUTES;

if (map_shared)
flags |= MAP_GPA_SHARED;
@@ -108,19 +109,19 @@ static void guest_map_private(uint64_t gpa, uint64_t size, bool do_fallocate)
guest_map_mem(gpa, size, false, do_fallocate);
}

-static void guest_run_test(uint64_t base_gpa, bool do_fallocate)
+struct {
+ uint64_t offset;
+ uint64_t size;
+} static const test_ranges[] = {
+ GUEST_STAGE(0, PAGE_SIZE),
+ GUEST_STAGE(0, SZ_2M),
+ GUEST_STAGE(PAGE_SIZE, PAGE_SIZE),
+ GUEST_STAGE(PAGE_SIZE, SZ_2M),
+ GUEST_STAGE(SZ_2M, PAGE_SIZE),
+};
+
+static void guest_test_explicit_conversion(uint64_t base_gpa, bool do_fallocate)
{
- struct {
- uint64_t offset;
- uint64_t size;
- uint8_t pattern;
- } stages[] = {
- GUEST_STAGE(0, PAGE_SIZE),
- GUEST_STAGE(0, SZ_2M),
- GUEST_STAGE(PAGE_SIZE, PAGE_SIZE),
- GUEST_STAGE(PAGE_SIZE, SZ_2M),
- GUEST_STAGE(SZ_2M, PAGE_SIZE),
- };
const uint8_t init_p = 0xcc;
uint64_t j;
int i;
@@ -130,9 +131,9 @@ static void guest_run_test(uint64_t base_gpa, bool do_fallocate)
guest_sync_shared(base_gpa, PER_CPU_DATA_SIZE, (uint8_t)~init_p, init_p);
memcmp_g(base_gpa, init_p, PER_CPU_DATA_SIZE);

- for (i = 0; i < ARRAY_SIZE(stages); i++) {
- uint64_t gpa = base_gpa + stages[i].offset;
- uint64_t size = stages[i].size;
+ for (i = 0; i < ARRAY_SIZE(test_ranges); i++) {
+ uint64_t gpa = base_gpa + test_ranges[i].offset;
+ uint64_t size = test_ranges[i].size;
uint8_t p1 = 0x11;
uint8_t p2 = 0x22;
uint8_t p3 = 0x33;
@@ -214,11 +215,11 @@ static void guest_run_test(uint64_t base_gpa, bool do_fallocate)
static void guest_code(uint64_t base_gpa)
{
/*
- * Run everything twice, with and without doing fallocate() on the
- * guest_memfd backing when converting between shared and private.
+ * Run the conversion test twice, with and without doing fallocate() on
+ * the guest_memfd backing when converting between shared and private.
*/
- guest_run_test(base_gpa, false);
- guest_run_test(base_gpa, true);
+ guest_test_explicit_conversion(base_gpa, false);
+ guest_test_explicit_conversion(base_gpa, true);
GUEST_DONE();
}

@@ -227,6 +228,7 @@ static void handle_exit_hypercall(struct kvm_vcpu *vcpu)
struct kvm_run *run = vcpu->run;
uint64_t gpa = run->hypercall.args[0];
uint64_t size = run->hypercall.args[1] * PAGE_SIZE;
+ bool set_attributes = run->hypercall.args[2] & MAP_GPA_SET_ATTRIBUTES;
bool map_shared = run->hypercall.args[2] & MAP_GPA_SHARED;
bool do_fallocate = run->hypercall.args[2] & MAP_GPA_DO_FALLOCATE;
struct kvm_vm *vm = vcpu->vm;
@@ -238,8 +240,9 @@ static void handle_exit_hypercall(struct kvm_vcpu *vcpu)
if (do_fallocate)
vm_guest_mem_fallocate(vm, gpa, size, map_shared);

- vm_set_memory_attributes(vm, gpa, size,
- map_shared ? 0 : KVM_MEMORY_ATTRIBUTE_PRIVATE);
+ if (set_attributes)
+ vm_set_memory_attributes(vm, gpa, size,
+ map_shared ? 0 : KVM_MEMORY_ATTRIBUTE_PRIVATE);
run->hypercall.ret = 0;
}

--
2.42.0.515.g380fc7ccd1-goog