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authorDavid Matlack <dmatlack@google.com>2021-05-21 20:38:28 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2021-05-27 14:45:54 +0300
commitef4c9f4f654622fa15b7a94a9bd1f19e76bb7feb (patch)
tree696ca6602c9a16c7b3f536f604831eb738b1a364 /tools
parentcad347fab142bcb9bebc125b5ba0c1e52ce74fdc (diff)
downloadlinux-ef4c9f4f654622fa15b7a94a9bd1f19e76bb7feb.tar.xz
KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()
vm_get_max_gfn() casts vm->max_gfn from a uint64_t to an unsigned int, which causes the upper 32-bits of the max_gfn to get truncated. Nobody noticed until now likely because vm_get_max_gfn() is only used as a mechanism to create a memslot in an unused region of the guest physical address space (the top), and the top of the 32-bit physical address space was always good enough. This fix reveals a bug in memslot_modification_stress_test which was trying to create a dummy memslot past the end of guest physical memory. Fix that by moving the dummy memslot lower. Fixes: 52200d0d944e ("KVM: selftests: Remove duplicate guest mode handling") Reviewed-by: Venkatesh Srinivas <venkateshs@chromium.org> Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210521173828.1180619-1-dmatlack@google.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/kvm/include/kvm_util.h2
-rw-r--r--tools/testing/selftests/kvm/lib/kvm_util.c2
-rw-r--r--tools/testing/selftests/kvm/lib/perf_test_util.c4
-rw-r--r--tools/testing/selftests/kvm/memslot_modification_stress_test.c18
4 files changed, 16 insertions, 10 deletions
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index a8f022794ce3..2e0d253dabd6 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -302,7 +302,7 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm);
unsigned int vm_get_page_size(struct kvm_vm *vm);
unsigned int vm_get_page_shift(struct kvm_vm *vm);
-unsigned int vm_get_max_gfn(struct kvm_vm *vm);
+uint64_t vm_get_max_gfn(struct kvm_vm *vm);
int vm_get_fd(struct kvm_vm *vm);
unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 1255744758e3..ea3f0db85b3e 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2117,7 +2117,7 @@ unsigned int vm_get_page_shift(struct kvm_vm *vm)
return vm->page_shift;
}
-unsigned int vm_get_max_gfn(struct kvm_vm *vm)
+uint64_t vm_get_max_gfn(struct kvm_vm *vm)
{
return vm->max_gfn;
}
diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
index 81490b9b4e32..abf381800a59 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2020, Google LLC.
*/
+#include <inttypes.h>
#include "kvm_util.h"
#include "perf_test_util.h"
@@ -80,7 +81,8 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
*/
TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm),
"Requested more guest memory than address space allows.\n"
- " guest pages: %lx max gfn: %x vcpus: %d wss: %lx]\n",
+ " guest pages: %" PRIx64 " max gfn: %" PRIx64
+ " vcpus: %d wss: %" PRIx64 "]\n",
guest_num_pages, vm_get_max_gfn(vm), vcpus,
vcpu_memory_bytes);
diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
index 6096bf0a5b34..98351ba0933c 100644
--- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c
+++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
@@ -71,14 +71,22 @@ struct memslot_antagonist_args {
};
static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
- uint64_t nr_modifications, uint64_t gpa)
+ uint64_t nr_modifications)
{
+ const uint64_t pages = 1;
+ uint64_t gpa;
int i;
+ /*
+ * Add the dummy memslot just below the perf_test_util memslot, which is
+ * at the top of the guest physical address space.
+ */
+ gpa = guest_test_phys_mem - pages * vm_get_page_size(vm);
+
for (i = 0; i < nr_modifications; i++) {
usleep(delay);
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
- DUMMY_MEMSLOT_INDEX, 1, 0);
+ DUMMY_MEMSLOT_INDEX, pages, 0);
vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
}
@@ -120,11 +128,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
pr_info("Started all vCPUs\n");
add_remove_memslot(vm, p->memslot_modification_delay,
- p->nr_memslot_modifications,
- guest_test_phys_mem +
- (guest_percpu_mem_size * nr_vcpus) +
- perf_test_args.host_page_size +
- perf_test_args.guest_page_size);
+ p->nr_memslot_modifications);
run_vcpus = false;