[RFC PATCH 2/2] KVM: arm64: selftests: Test VGICv3 redistributor region retry
Karl Mehltretter
kmehltretter at gmail.com
Sun Aug 9 23:52:17 PDT 2026
The existing redistributor-region test already adds valid partial
regions, rejects a later region that collides with the distributor, and
retries with a valid region. Its guest code does not access a
redistributor, so it misses redistributor MMIO bus entries lost by the
failed rollback.
Run a guest that reads GICR_TYPER from the second redistributor in the
original region and verifies its processor number. Put the test layout
outside the default guest memory slot so an absent iodev results in a
KVM_EXIT_MMIO instead of an ordinary RAM access.
Allow the common VGIC setup helper to select the guest entry point so the
retry case can reuse the normal test setup.
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Karl Mehltretter <kmehltretter at gmail.com>
---
tools/testing/selftests/kvm/arm64/vgic_init.c | 115 +++++++++++++-----
1 file changed, 86 insertions(+), 29 deletions(-)
diff --git a/tools/testing/selftests/kvm/arm64/vgic_init.c b/tools/testing/selftests/kvm/arm64/vgic_init.c
index 47e34b43afb29..8b321a1409b34 100644
--- a/tools/testing/selftests/kvm/arm64/vgic_init.c
+++ b/tools/testing/selftests/kvm/arm64/vgic_init.c
@@ -5,6 +5,7 @@
* Copyright (C) 2020, Red Hat, Inc.
*/
#include <linux/kernel.h>
+#include <linux/sizes.h>
#include <sys/syscall.h>
#include <asm/kvm.h>
#include <asm/kvm_para.h>
@@ -13,12 +14,23 @@
#include "test_util.h"
#include "kvm_util.h"
+#include "gic.h"
#include "processor.h"
+#include "ucall_common.h"
#include "vgic.h"
#include "gic_v3.h"
#define NR_VCPUS 4
+/* Keep the redistributor range outside the default guest memory slot. */
+#define REDIST_TEST_REGION0_BASE GICR_BASE_GPA
+#define REDIST_TEST_REGION1_BASE \
+ (REDIST_TEST_REGION0_BASE + 2 * KVM_VGIC_V3_REDIST_SIZE)
+#define REDIST_TEST_DIST_BASE \
+ (REDIST_TEST_REGION1_BASE + KVM_VGIC_V3_REDIST_SIZE)
+#define REDIST_TEST_REGION2_BASE \
+ (REDIST_TEST_DIST_BASE + KVM_VGIC_V3_DIST_SIZE)
+
#define REG_OFFSET(vcpu, offset) (((u64)vcpu << 32) | offset)
#define VGIC_DEV_IS_V2(_d) ((_d) == KVM_DEV_TYPE_ARM_VGIC_V2)
@@ -65,6 +77,16 @@ static void guest_code(void)
GUEST_DONE();
}
+static void guest_read_second_redist(void)
+{
+ u64 typer = readq((void *)(unsigned long)(REDIST_TEST_REGION0_BASE +
+ KVM_VGIC_V3_REDIST_SIZE +
+ GICR_TYPER));
+
+ GUEST_ASSERT_EQ(GICR_TYPER_CPU_NUMBER(typer), 1);
+ GUEST_DONE();
+}
+
/* we don't want to assert on run execution, hence that helper */
static int run_vcpu(struct kvm_vcpu *vcpu)
{
@@ -73,12 +95,13 @@ static int run_vcpu(struct kvm_vcpu *vcpu)
static struct vm_gic vm_gic_create_with_vcpus(u32 gic_dev_type,
u32 nr_vcpus,
+ void (*guest_fn)(void),
struct kvm_vcpu *vcpus[])
{
struct vm_gic v;
v.gic_dev_type = gic_dev_type;
- v.vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
+ v.vm = vm_create_with_vcpus(nr_vcpus, guest_fn, vcpus);
v.gic_fd = kvm_create_device(v.vm, gic_dev_type);
return v;
@@ -240,38 +263,40 @@ static void subtest_v3_redist_regions(struct vm_gic *v)
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL, "redist region attr value with count== 0");
- addr = REDIST_REGION_ATTR_ADDR(2, 0x200000, 0, 1);
+ addr = REDIST_REGION_ATTR_ADDR(2, REDIST_TEST_REGION0_BASE, 0, 1);
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL,
"attempt to register the first rdist region with index != 0");
- addr = REDIST_REGION_ATTR_ADDR(2, 0x201000, 0, 1);
+ addr = REDIST_REGION_ATTR_ADDR(2, REDIST_TEST_REGION0_BASE + 0x1000,
+ 0, 1);
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL, "rdist region with misaligned address");
- addr = REDIST_REGION_ATTR_ADDR(2, 0x200000, 0, 0);
+ addr = REDIST_REGION_ATTR_ADDR(2, REDIST_TEST_REGION0_BASE, 0, 0);
kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
- addr = REDIST_REGION_ATTR_ADDR(2, 0x200000, 0, 1);
+ addr = REDIST_REGION_ATTR_ADDR(2, REDIST_TEST_REGION0_BASE, 0, 1);
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL, "register an rdist region with already used index");
- addr = REDIST_REGION_ATTR_ADDR(1, 0x210000, 0, 2);
+ addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_REGION0_BASE + 0x10000,
+ 0, 2);
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL,
"register an rdist region overlapping with another one");
- addr = REDIST_REGION_ATTR_ADDR(1, 0x240000, 0, 2);
+ addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_REGION1_BASE, 0, 2);
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL, "register redist region with index not +1");
- addr = REDIST_REGION_ATTR_ADDR(1, 0x240000, 0, 1);
+ addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_REGION1_BASE, 0, 1);
kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
@@ -288,7 +313,7 @@ static void subtest_v3_redist_regions(struct vm_gic *v)
TEST_ASSERT(ret && errno == E2BIG,
"register redist region with top address beyond IPA range");
- addr = 0x260000;
+ addr = REDIST_TEST_DIST_BASE;
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST, &addr);
TEST_ASSERT(ret && errno == EINVAL,
@@ -296,19 +321,19 @@ static void subtest_v3_redist_regions(struct vm_gic *v)
/*
* Now there are 2 redist regions:
- * region 0 @ 0x200000 2 redists
- * region 1 @ 0x240000 1 redist
+ * region 0 has 2 redistributors
+ * region 1 has 1 redistributor
* Attempt to read their characteristics
*/
addr = REDIST_REGION_ATTR_ADDR(0, 0, 0, 0);
- expected_addr = REDIST_REGION_ATTR_ADDR(2, 0x200000, 0, 0);
+ expected_addr = REDIST_REGION_ATTR_ADDR(2, REDIST_TEST_REGION0_BASE, 0, 0);
ret = __kvm_device_attr_get(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(!ret && addr == expected_addr, "read characteristics of region #0");
addr = REDIST_REGION_ATTR_ADDR(0, 0, 0, 1);
- expected_addr = REDIST_REGION_ATTR_ADDR(1, 0x240000, 0, 1);
+ expected_addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_REGION1_BASE, 0, 1);
ret = __kvm_device_attr_get(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(!ret && addr == expected_addr, "read characteristics of region #1");
@@ -318,11 +343,11 @@ static void subtest_v3_redist_regions(struct vm_gic *v)
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == ENOENT, "read characteristics of non existing region");
- addr = 0x260000;
+ addr = REDIST_TEST_DIST_BASE;
kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_DIST, &addr);
- addr = REDIST_REGION_ATTR_ADDR(1, 0x260000, 0, 2);
+ addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_DIST_BASE, 0, 2);
ret = __kvm_device_attr_set(v->gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
TEST_ASSERT(ret && errno == EINVAL, "register redist region colliding with dist");
@@ -338,7 +363,7 @@ static void test_vgic_then_vcpus(u32 gic_dev_type)
struct vm_gic v;
int ret, i;
- v = vm_gic_create_with_vcpus(gic_dev_type, 1, vcpus);
+ v = vm_gic_create_with_vcpus(gic_dev_type, 1, guest_code, vcpus);
subtest_dist_rdist(&v);
@@ -359,7 +384,8 @@ static void test_vcpus_then_vgic(u32 gic_dev_type)
struct vm_gic v;
int ret;
- v = vm_gic_create_with_vcpus(gic_dev_type, NR_VCPUS, vcpus);
+ v = vm_gic_create_with_vcpus(gic_dev_type, NR_VCPUS, guest_code,
+ vcpus);
subtest_dist_rdist(&v);
@@ -403,6 +429,29 @@ static void test_v2_uaccess_cpuif_no_vcpus(void)
vm_gic_destroy(&v);
}
+static void run_vcpu_expect_done(struct kvm_vcpu *vcpu)
+{
+ struct ucall uc;
+
+ vcpu_run(vcpu);
+
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_DONE:
+ return;
+ case UCALL_ABORT:
+ REPORT_GUEST_ASSERT(uc);
+ break;
+ case UCALL_NONE:
+ if (vcpu->run->exit_reason == KVM_EXIT_MMIO)
+ TEST_FAIL("Unexpected MMIO exit at 0x%llx",
+ vcpu->run->mmio.phys_addr);
+ fallthrough;
+ default:
+ TEST_FAIL("Unexpected ucall %lu, exit_reason %u",
+ uc.cmd, vcpu->run->exit_reason);
+ }
+}
+
static void test_v3_new_redist_regions(void)
{
struct kvm_vcpu *vcpus[NR_VCPUS];
@@ -411,7 +460,8 @@ static void test_v3_new_redist_regions(void)
u64 addr;
int ret;
- v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS, vcpus);
+ v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS,
+ guest_code, vcpus);
subtest_v3_redist_regions(&v);
kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
KVM_DEV_ARM_VGIC_CTRL_INIT, NULL);
@@ -420,12 +470,13 @@ static void test_v3_new_redist_regions(void)
TEST_ASSERT(ret == -ENXIO, "running without sufficient number of rdists");
vm_gic_destroy(&v);
- /* step2 */
+ /* Step 2: adding enough redistributors after KVM_RUN is rejected. */
- v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS, vcpus);
+ v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS,
+ guest_code, vcpus);
subtest_v3_redist_regions(&v);
- addr = REDIST_REGION_ATTR_ADDR(1, 0x280000, 0, 2);
+ addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_REGION2_BASE, 0, 2);
kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
@@ -434,9 +485,10 @@ static void test_v3_new_redist_regions(void)
vm_gic_destroy(&v);
- /* step 3 */
+ /* Step 3: retry the failed region setup and exercise an existing rdist. */
- v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS, vcpus);
+ v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS,
+ guest_read_second_redist, vcpus);
subtest_v3_redist_regions(&v);
ret = __kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
@@ -444,15 +496,17 @@ static void test_v3_new_redist_regions(void)
TEST_ASSERT(ret && errno == EFAULT,
"register a third region allowing to cover the 4 vcpus");
- addr = REDIST_REGION_ATTR_ADDR(1, 0x280000, 0, 2);
+ addr = REDIST_REGION_ATTR_ADDR(1, REDIST_TEST_REGION2_BASE, 0, 2);
kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_ADDR,
KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION, &addr);
+ virt_map(v.vm, REDIST_TEST_REGION0_BASE, REDIST_TEST_REGION0_BASE,
+ vm_calc_num_guest_pages(v.vm->mode,
+ 2 * KVM_VGIC_V3_REDIST_SIZE));
kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
KVM_DEV_ARM_VGIC_CTRL_INIT, NULL);
- ret = run_vcpu(vcpus[3]);
- TEST_ASSERT(!ret, "vcpu run");
+ run_vcpu_expect_done(vcpus[0]);
vm_gic_destroy(&v);
}
@@ -608,7 +662,8 @@ static void test_v3_redist_ipa_range_check_at_vcpu_run(void)
int ret, i;
u64 addr;
- v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, 1, vcpus);
+ v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, 1,
+ guest_code, vcpus);
/* Set space for 3 redists, we have 1 vcpu, so this succeeds. */
addr = max_phys_size - (3 * 2 * 0x10000);
@@ -641,7 +696,8 @@ static void test_v3_its_region(void)
u64 addr;
int its_fd, ret;
- v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS, vcpus);
+ v = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS,
+ guest_code, vcpus);
its_fd = kvm_create_device(v.vm, KVM_DEV_TYPE_ARM_VGIC_ITS);
addr = 0x401000;
@@ -684,7 +740,8 @@ static void test_v3_nassgicap(void)
u32 typer2;
int ret;
- vm = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS, vcpus);
+ vm = vm_gic_create_with_vcpus(KVM_DEV_TYPE_ARM_VGIC_V3, NR_VCPUS,
+ guest_code, vcpus);
kvm_device_attr_get(vm.gic_fd, KVM_DEV_ARM_VGIC_GRP_DIST_REGS,
GICD_TYPER2, &typer2);
has_nassgicap = typer2 & GICD_TYPER2_nASSGIcap;
--
2.53.0
More information about the linux-arm-kernel
mailing list