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From: Josh Hilke <jrhilke@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	 David Matlack <dmatlack@google.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	 Josh Hilke <jrhilke@google.com>
Subject: [PATCH v5 02/21] KVM: selftests: Add guest read/write macros
Date: Thu,  4 Jun 2026 02:01:24 +0000	[thread overview]
Message-ID: <20260604020143.748245-3-jrhilke@google.com> (raw)
In-Reply-To: <20260604020143.748245-1-jrhilke@google.com>

From: David Matlack <dmatlack@google.com>

Add SYNC_FROM_GUEST_AND_READ(vm, variable), to read a variable value
from the guest. Add WRITE_AND_SYNC_TO_GUEST(vm, variable, value) to
write a value to a guest variable. These macros improve the readability
of code which reads and writes data between host and guest in tests.

Also update existing guest reads/writes to use these macros in the
following tests:
- tools/testing/selftests/kvm/dirty_log_test.c
- tools/testing/selftests/kvm/mmu_stress_test.c
- tools/testing/selftests/kvm/steal_time.c

No functional changes are intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Josh Hilke <jrhilke@google.com>
Signed-off-by: Josh Hilke <jrhilke@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/kvm/dirty_log_test.c  |  9 +++-----
 .../testing/selftests/kvm/include/kvm_util.h  | 10 +++++++++
 tools/testing/selftests/kvm/mmu_stress_test.c |  9 +++-----
 tools/testing/selftests/kvm/steal_time.c      | 22 +++++++------------
 4 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 12446a4b6e8d..561b80064230 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -698,8 +698,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 
 		sync_global_to_guest(vm, iteration);
 
-		WRITE_ONCE(nr_writes, 0);
-		sync_global_to_guest(vm, nr_writes);
+		WRITE_AND_SYNC_TO_GUEST(vm, nr_writes, 0);
 
 		dirty_ring_prev_iteration_last_page = dirty_ring_last_page;
 		WRITE_ONCE(dirty_ring_vcpu_ring_full, false);
@@ -761,16 +760,14 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 		 * writing memory during verification, pages that this thread
 		 * sees as clean may be written with this iteration's value.
 		 */
-		WRITE_ONCE(vcpu_stop, true);
-		sync_global_to_guest(vm, vcpu_stop);
+		WRITE_AND_SYNC_TO_GUEST(vm, vcpu_stop, true);
 		sem_wait(&sem_vcpu_stop);
 
 		/*
 		 * Clear vcpu_stop after the vCPU thread has acknowledge the
 		 * stop request and is waiting, i.e. is definitely not running!
 		 */
-		WRITE_ONCE(vcpu_stop, false);
-		sync_global_to_guest(vm, vcpu_stop);
+		WRITE_AND_SYNC_TO_GUEST(vm, vcpu_stop, false);
 
 		/*
 		 * Sync the number of writes performed before verification, the
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 2ecaaa0e9965..88211d696a11 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -1138,6 +1138,16 @@ vm_adjust_num_guest_pages(enum vm_guest_mode mode, unsigned int num_guest_pages)
 	memcpy(&(g), _p, sizeof(g));				\
 })
 
+#define SYNC_FROM_GUEST_AND_READ(_vm, _variable) ({		\
+	sync_global_from_guest(_vm, _variable);			\
+	READ_ONCE(_variable);					\
+})
+
+#define WRITE_AND_SYNC_TO_GUEST(_vm, _variable, _value) do {	\
+	WRITE_ONCE(_variable, _value);				\
+	sync_global_to_guest(_vm, _variable);			\
+} while (0)
+
 /*
  * Write a global value, but only in the VM's (guest's) domain.  Primarily used
  * for "globals" that hold per-VM values (VMs always duplicate code and global
diff --git a/tools/testing/selftests/kvm/mmu_stress_test.c b/tools/testing/selftests/kvm/mmu_stress_test.c
index 54d281419d31..473ef4c0ea9f 100644
--- a/tools/testing/selftests/kvm/mmu_stress_test.c
+++ b/tools/testing/selftests/kvm/mmu_stress_test.c
@@ -155,10 +155,8 @@ static void *vcpu_worker(void *data)
 		    "Expected EFAULT on write to RO memory, got r = %d, errno = %d", r, errno);
 
 	atomic_inc(&nr_ro_faults);
-	if (atomic_read(&nr_ro_faults) == nr_vcpus) {
-		WRITE_ONCE(all_vcpus_hit_ro_fault, true);
-		sync_global_to_guest(vm, all_vcpus_hit_ro_fault);
-	}
+	if (atomic_read(&nr_ro_faults) == nr_vcpus)
+		WRITE_AND_SYNC_TO_GUEST(vm, all_vcpus_hit_ro_fault, true);
 
 #if defined(__x86_64__) || defined(__aarch64__)
 	/*
@@ -383,8 +381,7 @@ int main(int argc, char *argv[])
 	rendezvous_with_vcpus(&time_run2, "run 2");
 
 	mprotect(mem, slot_size, PROT_READ);
-	mprotect_ro_done = true;
-	sync_global_to_guest(vm, mprotect_ro_done);
+	WRITE_AND_SYNC_TO_GUEST(vm, mprotect_ro_done, true);
 
 	rendezvous_with_vcpus(&time_ro, "mprotect RO");
 	mprotect(mem, slot_size, PROT_READ | PROT_WRITE);
diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
index 76fcdd1fd3cb..2de87549fcc0 100644
--- a/tools/testing/selftests/kvm/steal_time.c
+++ b/tools/testing/selftests/kvm/steal_time.c
@@ -70,8 +70,8 @@ static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
 static void steal_time_init(struct kvm_vcpu *vcpu, u32 i)
 {
 	/* ST_GPA_BASE is identity mapped */
-	st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
-	sync_global_to_guest(vcpu->vm, st_gva[i]);
+	WRITE_AND_SYNC_TO_GUEST(vcpu->vm, st_gva[i],
+				(void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE));
 
 	vcpu_set_msr(vcpu, MSR_KVM_STEAL_TIME, (ulong)st_gva[i] | KVM_MSR_ENABLED);
 }
@@ -187,8 +187,7 @@ static void steal_time_init(struct kvm_vcpu *vcpu, u32 i)
 	};
 
 	/* ST_GPA_BASE is identity mapped */
-	st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
-	sync_global_to_guest(vm, st_gva[i]);
+	WRITE_AND_SYNC_TO_GUEST(vm, st_gva[i], (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE));
 
 	st_ipa = (ulong)st_gva[i];
 	vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);
@@ -310,10 +309,8 @@ static bool is_steal_time_supported(struct kvm_vcpu *vcpu)
 static void steal_time_init(struct kvm_vcpu *vcpu, u32 i)
 {
 	/* ST_GPA_BASE is identity mapped */
-	st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
-	st_gpa[i] = addr_gva2gpa(vcpu->vm, (gva_t)st_gva[i]);
-	sync_global_to_guest(vcpu->vm, st_gva[i]);
-	sync_global_to_guest(vcpu->vm, st_gpa[i]);
+	WRITE_AND_SYNC_TO_GUEST(vcpu->vm, st_gva[i], (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE));
+	WRITE_AND_SYNC_TO_GUEST(vcpu->vm, st_gpa[i], addr_gva2gpa(vcpu->vm, (gva_t)st_gva[i]));
 }
 
 static void steal_time_dump(struct kvm_vm *vm, u32 vcpu_idx)
@@ -442,8 +439,7 @@ static void steal_time_init(struct kvm_vcpu *vcpu, u32 i)
 	};
 
 	/* ST_GPA_BASE is identity mapped */
-	st_gva[i] = (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE);
-	sync_global_to_guest(vm, st_gva[i]);
+	WRITE_AND_SYNC_TO_GUEST(vm, st_gva[i], (void *)(ST_GPA_BASE + i * STEAL_TIME_SIZE));
 
 	err = __vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &attr);
 	TEST_ASSERT(err == 0, "No PV stealtime Feature");
@@ -549,8 +545,7 @@ int main(int ac, char **av)
 
 		/* Second VCPU run, expect guest stolen time to be <= run_delay */
 		run_vcpu(vcpus[i]);
-		sync_global_from_guest(vm, guest_stolen_time[i]);
-		stolen_time = guest_stolen_time[i];
+		stolen_time = SYNC_FROM_GUEST_AND_READ(vm, guest_stolen_time[i]);
 		run_delay = get_run_delay();
 		TEST_ASSERT(stolen_time <= run_delay,
 			    "Expected stolen time <= %ld, got %ld",
@@ -570,8 +565,7 @@ int main(int ac, char **av)
 
 		/* Run VCPU again to confirm stolen time is consistent with run_delay */
 		run_vcpu(vcpus[i]);
-		sync_global_from_guest(vm, guest_stolen_time[i]);
-		stolen_time = guest_stolen_time[i] - stolen_time;
+		stolen_time = SYNC_FROM_GUEST_AND_READ(vm, guest_stolen_time[i]) - stolen_time;
 		TEST_ASSERT(stolen_time >= run_delay,
 			    "Expected stolen time >= %ld, got %ld",
 			    run_delay, stolen_time);
-- 
2.54.0.1032.g2f8565e1d1-goog


  parent reply	other threads:[~2026-06-04  2:02 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-04  2:01 [PATCH v5 00/21] KVM: selftests: Link with VFIO selftests lib and test device interrupts Josh Hilke
2026-06-04  2:01 ` [PATCH v5 01/21] KVM: selftests: Build and link selftests/vfio/lib into KVM selftests Josh Hilke
2026-06-04  2:01 ` Josh Hilke [this message]
2026-06-04  2:01 ` [PATCH v5 03/21] KVM: selftests: Rename guest_rng to kvm_rng Josh Hilke
2026-06-04  2:01 ` [PATCH v5 04/21] KVM: selftests: Add helper to generate random u64 in range [min,max] Josh Hilke
2026-06-04  2:01 ` [PATCH v5 05/21] KVM: selftests: Add IRQ injection test Josh Hilke
2026-06-04 16:19   ` Sean Christopherson
2026-06-04 16:26     ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 06/21] KVM: selftests: Add helper to get host IRQ from device MSIX for IRQ bypass test Josh Hilke
2026-06-04  2:01 ` [PATCH v5 07/21] KVM: selftests: Verify IRQ bypass works in IRQ test Josh Hilke
2026-06-04 16:22   ` Sean Christopherson
2026-06-04 17:56   ` Sean Christopherson
2026-06-04 19:25     ` Sean Christopherson
2026-06-04 19:52       ` Sean Christopherson
2026-06-04 23:14       ` Sean Christopherson
2026-06-04 23:35         ` David Matlack
2026-06-04  2:01 ` [PATCH v5 08/21] KVM: selftests: Add helpers to write proc IRQ affinity for " Josh Hilke
2026-06-04 19:35   ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 09/21] KVM: selftests: Add helpers to print " Josh Hilke
2026-06-04  2:01 ` [PATCH v5 10/21] KVM: selftests: Verify interrupts are received when IRQ affinity changes in " Josh Hilke
2026-06-04  2:01 ` [PATCH v5 11/21] KVM: selftests: Verify IRQs wake up halted vCPUs " Josh Hilke
2026-06-04  2:01 ` [PATCH v5 12/21] KVM: selftests: Verify interrupts are received after modifying IRQ routes " Josh Hilke
2026-06-04 17:22   ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 13/21] KVM: selftests: Make number of IRQs configurable " Josh Hilke
2026-06-04 17:35   ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 14/21] KVM: selftests: Verify non-postable IRQ remapping " Josh Hilke
2026-06-04 17:22   ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 15/21] KVM: selftests: Add kvm_gettid() wrapper and convert users Josh Hilke
2026-06-04  2:01 ` [PATCH v5 16/21] KVM: selftests: Add kvm_sched_getaffinity() " Josh Hilke
2026-06-04 17:23   ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 17/21] KVM: selftests: Add pin_task_to_random_cpu() helper function for IRQ test Josh Hilke
2026-06-04  2:01 ` [PATCH v5 18/21] KVM: selftests: Verify vCPU migration during IRQ delivery in " Josh Hilke
2026-06-04 17:27   ` Sean Christopherson
2026-06-04  2:01 ` [PATCH v5 19/21] KVM: selftests: Print vCPU affinity on timeout during " Josh Hilke
2026-06-04  2:01 ` [PATCH v5 20/21] KVM: selftests: Make number of vCPUs configurable in " Josh Hilke
2026-06-04  2:01 ` [PATCH v5 21/21] KVM: selftests: Add xAPIC support " Josh Hilke
2026-06-04 20:22 ` [PATCH v5 00/21] KVM: selftests: Link with VFIO selftests lib and test device interrupts Sean Christopherson

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