KVM Archive mirror
 help / color / mirror / Atom feed
From: Oliver Upton <oliver.upton@linux.dev>
To: kvmarm@lists.linux.dev
Cc: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Zenghui Yu <yuzenghui@huawei.com>,
	kvm@vger.kernel.org, Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH 2/2] KVM: selftests: Add test for uaccesses to non-existent vgic-v2 CPUIF
Date: Wed, 24 Apr 2024 17:39:59 +0000	[thread overview]
Message-ID: <20240424173959.3776798-3-oliver.upton@linux.dev> (raw)
In-Reply-To: <20240424173959.3776798-1-oliver.upton@linux.dev>

Assert that accesses to a non-existent vgic-v2 CPU interface
consistently fail across the various KVM device attr ioctls. This also
serves as a regression test for a bug wherein KVM hits a NULL
dereference when the CPUID specified in the ioctl is invalid.

Note that there is no need to print the observed errno, as TEST_ASSERT()
will take care of it.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 .../testing/selftests/kvm/aarch64/vgic_init.c | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/vgic_init.c b/tools/testing/selftests/kvm/aarch64/vgic_init.c
index eef816b80993..ca917c71ff60 100644
--- a/tools/testing/selftests/kvm/aarch64/vgic_init.c
+++ b/tools/testing/selftests/kvm/aarch64/vgic_init.c
@@ -84,6 +84,18 @@ static struct vm_gic vm_gic_create_with_vcpus(uint32_t gic_dev_type,
 	return v;
 }
 
+static struct vm_gic vm_gic_create_barebones(uint32_t gic_dev_type)
+{
+	struct vm_gic v;
+
+	v.gic_dev_type = gic_dev_type;
+	v.vm = vm_create_barebones();
+	v.gic_fd = kvm_create_device(v.vm, gic_dev_type);
+
+	return v;
+}
+
+
 static void vm_gic_destroy(struct vm_gic *v)
 {
 	close(v->gic_fd);
@@ -357,6 +369,40 @@ static void test_vcpus_then_vgic(uint32_t gic_dev_type)
 	vm_gic_destroy(&v);
 }
 
+#define KVM_VGIC_V2_ATTR(offset, cpu) \
+	(FIELD_PREP(KVM_DEV_ARM_VGIC_OFFSET_MASK, offset) | \
+	 FIELD_PREP(KVM_DEV_ARM_VGIC_CPUID_MASK, cpu))
+
+#define GIC_CPU_CTRL	0x00
+
+static void test_v2_uaccess_cpuif_no_vcpus(void)
+{
+	struct vm_gic v;
+	u64 val = 0;
+	int ret;
+
+	v = vm_gic_create_barebones(KVM_DEV_TYPE_ARM_VGIC_V2);
+	subtest_dist_rdist(&v);
+
+	ret = __kvm_has_device_attr(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CPU_REGS,
+				    KVM_VGIC_V2_ATTR(GIC_CPU_CTRL, 0));
+	TEST_ASSERT(ret && errno == EINVAL,
+		    "accessed non-existent CPU interface, want errno: %i",
+		    EINVAL);
+	ret = __kvm_device_attr_get(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CPU_REGS,
+				    KVM_VGIC_V2_ATTR(GIC_CPU_CTRL, 0), &val);
+	TEST_ASSERT(ret && errno == EINVAL,
+		    "accessed non-existent CPU interface, want errno: %i",
+		    EINVAL);
+	ret = __kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CPU_REGS,
+				    KVM_VGIC_V2_ATTR(GIC_CPU_CTRL, 0), &val);
+	TEST_ASSERT(ret && errno == EINVAL,
+		    "accessed non-existent CPU interface, want errno: %i",
+		    EINVAL);
+
+	vm_gic_destroy(&v);
+}
+
 static void test_v3_new_redist_regions(void)
 {
 	struct kvm_vcpu *vcpus[NR_VCPUS];
@@ -675,6 +721,9 @@ void run_tests(uint32_t gic_dev_type)
 	test_vcpus_then_vgic(gic_dev_type);
 	test_vgic_then_vcpus(gic_dev_type);
 
+	if (VGIC_DEV_IS_V2(gic_dev_type))
+		test_v2_uaccess_cpuif_no_vcpus();
+
 	if (VGIC_DEV_IS_V3(gic_dev_type)) {
 		test_v3_new_redist_regions();
 		test_v3_typer_accesses();
-- 
2.44.0.769.g3c40516874-goog


  parent reply	other threads:[~2024-04-24 17:40 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-24 17:39 [PATCH 0/2] KVM: arm64: Avoid NULL dereference in vgic-v2 device attr accessors Oliver Upton
2024-04-24 17:39 ` [PATCH 1/2] KVM: arm64: vgic-v2: Check for non-NULL vCPU in vgic_v2_parse_attr() Oliver Upton
2024-04-24 17:39 ` Oliver Upton [this message]
2024-04-24 18:06 ` [PATCH 0/2] KVM: arm64: Avoid NULL dereference in vgic-v2 device attr accessors Marc Zyngier
2024-04-24 19:15 ` Oliver Upton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240424173959.3776798-3-oliver.upton@linux.dev \
    --to=oliver.upton@linux.dev \
    --cc=dvyukov@google.com \
    --cc=glider@google.com \
    --cc=james.morse@arm.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.linux.dev \
    --cc=maz@kernel.org \
    --cc=suzuki.poulose@arm.com \
    --cc=yuzenghui@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).