[PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[David Matlack]

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>
---

v1 -> v2:
 - Added Venkatesh's R-b line.
 - Used PRIx64 to print uint64_t instead of %lx.

 tools/testing/selftests/kvm/include/kvm_util.h |  2 +-
 tools/testing/selftests/kvm/lib/kvm_util.c     |  2 +-
 .../testing/selftests/kvm/lib/perf_test_util.c |  4 +++-
 .../kvm/memslot_modification_stress_test.c     | 18 +++++++++++-------
 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 84982eb02b29..5d9b35d09251 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -303,7 +303,7 @@ 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 1af1009254c4..aeffbb1e7c7d 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2058,7 +2058,7 @@ 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;
 
-- 
2.31.1.818.g46aad6cb9e-goog

Re: [PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[Peter Xu]

On Fri, May 21, 2021 at 05:38:28PM +0000, David Matlack wrote:
> 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>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu

Re: [PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[Andrew Jones]

On Fri, May 21, 2021 at 05:38:28PM +0000, David Matlack wrote:
> 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>
> ---
> 
> v1 -> v2:
>  - Added Venkatesh's R-b line.
>  - Used PRIx64 to print uint64_t instead of %lx.
> 
>  tools/testing/selftests/kvm/include/kvm_util.h |  2 +-
>  tools/testing/selftests/kvm/lib/kvm_util.c     |  2 +-
>  .../testing/selftests/kvm/lib/perf_test_util.c |  4 +++-
>  .../kvm/memslot_modification_stress_test.c     | 18 +++++++++++-------
>  4 files changed, 16 insertions(+), 10 deletions(-)
>

Reviewed-by: Andrew Jones <drjones@redhat.com>

Thanks,
drew

Re: [PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[Paolo Bonzini]

On 21/05/21 19:38, David Matlack wrote:
> 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>
> ---
> 
> v1 -> v2:
>   - Added Venkatesh's R-b line.
>   - Used PRIx64 to print uint64_t instead of %lx.
> 
>   tools/testing/selftests/kvm/include/kvm_util.h |  2 +-
>   tools/testing/selftests/kvm/lib/kvm_util.c     |  2 +-
>   .../testing/selftests/kvm/lib/perf_test_util.c |  4 +++-
>   .../kvm/memslot_modification_stress_test.c     | 18 +++++++++++-------
>   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 84982eb02b29..5d9b35d09251 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -303,7 +303,7 @@ 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 1af1009254c4..aeffbb1e7c7d 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2058,7 +2058,7 @@ 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;
>   
> 

Queued, thanks.

Paolo

Re: [PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[Christian Borntraeger]

On 21.05.21 19:38, David Matlack wrote:
> 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>

As a heads up:
I have not yet looked into this, but this broke demand_paging_test and kvm_page_table_test
on s390:

not ok 4 selftests: kvm: demand_paging_test # exit=254
# selftests: kvm: dirty_log_test
# ==== Test Assertion Failure ====
#   lib/kvm_util.c:900: ret == 0
#   pid=245410 tid=245410 errno=22 - Invalid argument
#      1	0x0000000001005457: vm_userspace_mem_region_add at kvm_util.c:900
#      2	0x0000000001002cbf: run_test at dirty_log_test.c:757
#      3	 (inlined by) run_test at dirty_log_test.c:702
#      4	0x000000000100c055: for_each_guest_mode at guest_modes.c:37
#      5	0x00000000010022b5: main at dirty_log_test.c:929 (discriminator 3)
#      6	0x000003ff96fabdb3: ?? ??:0
#      7	0x000000000100241d: .annobin_lto.hot at crt1.o:?
#   KVM_SET_USER_MEMORY_REGION IOCTL failed,
#   rc: -1 errno: 22
#   slot: 1 flags: 0x1
#   guest_phys_addr: 0xfffffbfe00000 size: 0x40100000
# Test iterations: 32, interval: 10 (ms)
# Testing Log Mode 'dirty-log'
# Testing guest mode: PA-bits:52,  VA-bits:48,  4K pages
# guest physical test memory offset: 0xfffffbfe00000
not ok 5 selftests: kvm: dirty_log_test # exit=254
# selftests: kvm: kvm_create_max_vcpus
# KVM_CAP_MAX_VCPU_ID: 248
# KVM_CAP_MAX_VCPUS: 248
# Testing creating 248 vCPUs, with IDs 0...247.
ok 6 selftests: kvm: kvm_create_max_vcpus
# selftests: kvm: kvm_page_table_test
# ==== Test Assertion Failure ====
#   lib/kvm_util.c:900: ret == 0
#   pid=245454 tid=245454 errno=22 - Invalid argument
#      1	0x0000000001003e47: vm_userspace_mem_region_add at kvm_util.c:900
#      2	0x000000000100257d: pre_init_before_test at kvm_page_table_test.c:302
#      3	 (inlined by) run_test at kvm_page_table_test.c:374
#      4	0x000000000100aa45: for_each_guest_mode at guest_modes.c:37
#      5	0x0000000001001dd9: main at kvm_page_table_test.c:503
#      6	0x000003ff827abdb3: ?? ??:0
#      7	0x0000000001001e8d: .annobin_lto.hot at crt1.o:?
#   KVM_SET_USER_MEMORY_REGION IOCTL failed,
#   rc: -1 errno: 22
#   slot: 1 flags: 0x0
#   guest_phys_addr: 0xfffffbff00000 size: 0x40000000
not ok 7 selftests: kvm: kvm_page_table_test # exit=254


> ---
> 
> v1 -> v2:
>   - Added Venkatesh's R-b line.
>   - Used PRIx64 to print uint64_t instead of %lx.
> 
>   tools/testing/selftests/kvm/include/kvm_util.h |  2 +-
>   tools/testing/selftests/kvm/lib/kvm_util.c     |  2 +-
>   .../testing/selftests/kvm/lib/perf_test_util.c |  4 +++-
>   .../kvm/memslot_modification_stress_test.c     | 18 +++++++++++-------
>   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 84982eb02b29..5d9b35d09251 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -303,7 +303,7 @@ 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 1af1009254c4..aeffbb1e7c7d 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2058,7 +2058,7 @@ 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;
> 

Re: [PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()

[Christian Borntraeger]

On 08.06.21 10:39, Christian Borntraeger wrote:
> 
> 
> On 21.05.21 19:38, David Matlack wrote:
>> 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>
> 
> As a heads up:
> I have not yet looked into this, but this broke demand_paging_test and kvm_page_table_test
> on s390:
> 
> not ok 4 selftests: kvm: demand_paging_test # exit=254
> # selftests: kvm: dirty_log_test
> # ==== Test Assertion Failure ====
> #   lib/kvm_util.c:900: ret == 0
> #   pid=245410 tid=245410 errno=22 - Invalid argument
> #      1    0x0000000001005457: vm_userspace_mem_region_add at kvm_util.c:900
> #      2    0x0000000001002cbf: run_test at dirty_log_test.c:757
> #      3     (inlined by) run_test at dirty_log_test.c:702
> #      4    0x000000000100c055: for_each_guest_mode at guest_modes.c:37
> #      5    0x00000000010022b5: main at dirty_log_test.c:929 (discriminator 3)
> #      6    0x000003ff96fabdb3: ?? ??:0
> #      7    0x000000000100241d: .annobin_lto.hot at crt1.o:?
> #   KVM_SET_USER_MEMORY_REGION IOCTL failed,
> #   rc: -1 errno: 22
> #   slot: 1 flags: 0x1
> #   guest_phys_addr: 0xfffffbfe00000 size: 0x40100000

Ah. We do have a limit of 128TB for guest physical memory. The patch now made this
apparent as we no longer cut the upper bits off.

[PATCH] KVM: selftests: introduce P47V64 for s390x

[Christian Borntraeger]

s390x can have up to 47bits of physical guest and 64bits of virtual
address  bits. Add a new address mode to avoid errors of testcases
going beyond 47bits.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
 tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index fcd8e3855111..6d3f71822976 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -43,6 +43,7 @@ enum vm_guest_mode {
 	VM_MODE_P40V48_4K,
 	VM_MODE_P40V48_64K,
 	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
+	VM_MODE_P47V64_4K,	/* For 48bits VA but ANY bits PA */
 	NUM_VM_MODES,
 };
 
@@ -60,7 +61,7 @@ enum vm_guest_mode {
 
 #elif defined(__s390x__)
 
-#define VM_MODE_DEFAULT			VM_MODE_P52V48_4K
+#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
 #define MIN_PAGE_SHIFT			12U
 #define ptes_per_page(page_size)	((page_size) / 16)
 
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 28e528c19d28..d61ad15b1979 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -175,6 +175,7 @@ const char *vm_guest_mode_string(uint32_t i)
 		[VM_MODE_P40V48_4K]	= "PA-bits:40,  VA-bits:48,  4K pages",
 		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
 		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
+		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
 	};
 	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
 		       "Missing new mode strings?");
@@ -192,6 +193,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
 	{ 40, 48,  0x1000, 12 },
 	{ 40, 48, 0x10000, 16 },
 	{  0,  0,  0x1000, 12 },
+	{ 47, 64,  0x1000, 12 },
 };
 _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
 	       "Missing new mode params?");
@@ -277,6 +279,9 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
 		TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
 #endif
 		break;
+	case VM_MODE_P47V64_4K:
+		vm->pgtable_levels = 4;
+		break;
 	default:
 		TEST_FAIL("Unknown guest mode, mode: 0x%x", mode);
 	}
-- 
2.31.1

Re: [PATCH] KVM: selftests: introduce P47V64 for s390x

[Janosch Frank]

On 6/8/21 1:45 PM, Christian Borntraeger wrote:
> s390x can have up to 47bits of physical guest and 64bits of virtual
> address  bits. Add a new address mode to avoid errors of testcases
> going beyond 47bits.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
>  tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index fcd8e3855111..6d3f71822976 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -43,6 +43,7 @@ enum vm_guest_mode {
>  	VM_MODE_P40V48_4K,
>  	VM_MODE_P40V48_64K,
>  	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
> +	VM_MODE_P47V64_4K,	/* For 48bits VA but ANY bits PA */

/* 64 bits VA but 47 bits PA */

Or, looking at the other entries above, just remove it.

>  	NUM_VM_MODES,
>  };
>  
> @@ -60,7 +61,7 @@ enum vm_guest_mode {
>  
>  #elif defined(__s390x__)
>  
> -#define VM_MODE_DEFAULT			VM_MODE_P52V48_4K
> +#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
>  #define MIN_PAGE_SHIFT			12U
>  #define ptes_per_page(page_size)	((page_size) / 16)
>  
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 28e528c19d28..d61ad15b1979 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -175,6 +175,7 @@ const char *vm_guest_mode_string(uint32_t i)
>  		[VM_MODE_P40V48_4K]	= "PA-bits:40,  VA-bits:48,  4K pages",
>  		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
>  		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
> +		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
>  	};
>  	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
>  		       "Missing new mode strings?");
> @@ -192,6 +193,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
>  	{ 40, 48,  0x1000, 12 },
>  	{ 40, 48, 0x10000, 16 },
>  	{  0,  0,  0x1000, 12 },
> +	{ 47, 64,  0x1000, 12 },
>  };
>  _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
>  	       "Missing new mode params?");
> @@ -277,6 +279,9 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
>  		TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
>  #endif
>  		break;
> +	case VM_MODE_P47V64_4K:
> +		vm->pgtable_levels = 4;
> +		break;
>  	default:
>  		TEST_FAIL("Unknown guest mode, mode: 0x%x", mode);
>  	}
> 

Re: [PATCH] KVM: selftests: introduce P47V64 for s390x

[Christian Borntraeger]

On 08.06.21 13:49, Janosch Frank wrote:
> On 6/8/21 1:45 PM, Christian Borntraeger wrote:
>> s390x can have up to 47bits of physical guest and 64bits of virtual
>> address  bits. Add a new address mode to avoid errors of testcases
>> going beyond 47bits.
>>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> ---
>>   tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
>>   tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
>>   2 files changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
>> index fcd8e3855111..6d3f71822976 100644
>> --- a/tools/testing/selftests/kvm/include/kvm_util.h
>> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
>> @@ -43,6 +43,7 @@ enum vm_guest_mode {
>>   	VM_MODE_P40V48_4K,
>>   	VM_MODE_P40V48_64K,
>>   	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
>> +	VM_MODE_P47V64_4K,	/* For 48bits VA but ANY bits PA */
> 
> /* 64 bits VA but 47 bits PA */
> 
> Or, looking at the other entries above, just remove it.
Yes, will remove.

Re: [PATCH] KVM: selftests: introduce P47V64 for s390x

[Christian Borntraeger]

On 08.06.21 13:45, Christian Borntraeger wrote:
> s390x can have up to 47bits of physical guest and 64bits of virtual
> address  bits. Add a new address mode to avoid errors of testcases
> going beyond 47bits.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>   tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
>   tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
>   2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index fcd8e3855111..6d3f71822976 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -43,6 +43,7 @@ enum vm_guest_mode {
>   	VM_MODE_P40V48_4K,
>   	VM_MODE_P40V48_64K,
>   	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
> +	VM_MODE_P47V64_4K,	/* For 48bits VA but ANY bits PA */
>   	NUM_VM_MODES,
>   };
>   
> @@ -60,7 +61,7 @@ enum vm_guest_mode {
>   
>   #elif defined(__s390x__)
>   
> -#define VM_MODE_DEFAULT			VM_MODE_P52V48_4K
> +#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
>   #define MIN_PAGE_SHIFT			12U
>   #define ptes_per_page(page_size)	((page_size) / 16)
>   
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 28e528c19d28..d61ad15b1979 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -175,6 +175,7 @@ const char *vm_guest_mode_string(uint32_t i)
>   		[VM_MODE_P40V48_4K]	= "PA-bits:40,  VA-bits:48,  4K pages",
>   		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
>   		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
> +		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
>   	};
>   	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
>   		       "Missing new mode strings?");
> @@ -192,6 +193,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
>   	{ 40, 48,  0x1000, 12 },
>   	{ 40, 48, 0x10000, 16 },
>   	{  0,  0,  0x1000, 12 },
> +	{ 47, 64,  0x1000, 12 },
>   };
>   _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
>   	       "Missing new mode params?");
> @@ -277,6 +279,9 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
>   		TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
>   #endif
>   		break;
> +	case VM_MODE_P47V64_4K:
> +		vm->pgtable_levels = 4;

I will change that to 5 as well.

[PATCH v2] KVM: selftests: introduce P47V64 for s390x

[Christian Borntraeger]

s390x can have up to 47bits of physical guest and 64bits of virtual
address  bits. Add a new address mode to avoid errors of testcases
going beyond 47bits.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
v1->v2:
- remove wrong comment
- use 5 levels of page tables
 tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
 tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index fcd8e3855111..b602552b1ed0 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -43,6 +43,7 @@ enum vm_guest_mode {
 	VM_MODE_P40V48_4K,
 	VM_MODE_P40V48_64K,
 	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
+	VM_MODE_P47V64_4K,
 	NUM_VM_MODES,
 };
 
@@ -60,7 +61,7 @@ enum vm_guest_mode {
 
 #elif defined(__s390x__)
 
-#define VM_MODE_DEFAULT			VM_MODE_P52V48_4K
+#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
 #define MIN_PAGE_SHIFT			12U
 #define ptes_per_page(page_size)	((page_size) / 16)
 
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 28e528c19d28..b126fab6c4e1 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -175,6 +175,7 @@ const char *vm_guest_mode_string(uint32_t i)
 		[VM_MODE_P40V48_4K]	= "PA-bits:40,  VA-bits:48,  4K pages",
 		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
 		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
+		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
 	};
 	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
 		       "Missing new mode strings?");
@@ -192,6 +193,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
 	{ 40, 48,  0x1000, 12 },
 	{ 40, 48, 0x10000, 16 },
 	{  0,  0,  0x1000, 12 },
+	{ 47, 64,  0x1000, 12 },
 };
 _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
 	       "Missing new mode params?");
@@ -277,6 +279,9 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
 		TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
 #endif
 		break;
+	case VM_MODE_P47V64_4K:
+		vm->pgtable_levels = 5;
+		break;
 	default:
 		TEST_FAIL("Unknown guest mode, mode: 0x%x", mode);
 	}
-- 
2.31.1

Re: [PATCH v2] KVM: selftests: introduce P47V64 for s390x

[David Matlack]

On Tue, Jun 08, 2021 at 02:39:54PM +0200, Christian Borntraeger wrote:
> s390x can have up to 47bits of physical guest and 64bits of virtual
> address  bits. Add a new address mode to avoid errors of testcases
> going beyond 47bits.

Thanks for the fix. My apologies for breaking s390.

The patch "KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()"
has already been added to stable so you may want to add the following:

Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()")
Cc: stable@vger.kernel.org

> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Reviewed-by: David Matlack <dmatlack@google.com>

> ---
> v1->v2:
> - remove wrong comment
> - use 5 levels of page tables
>  tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
>  tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index fcd8e3855111..b602552b1ed0 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -43,6 +43,7 @@ enum vm_guest_mode {
>  	VM_MODE_P40V48_4K,
>  	VM_MODE_P40V48_64K,
>  	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
> +	VM_MODE_P47V64_4K,
>  	NUM_VM_MODES,
>  };
>  
> @@ -60,7 +61,7 @@ enum vm_guest_mode {
>  
>  #elif defined(__s390x__)
>  
> -#define VM_MODE_DEFAULT			VM_MODE_P52V48_4K
> +#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
>  #define MIN_PAGE_SHIFT			12U
>  #define ptes_per_page(page_size)	((page_size) / 16)
>  
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 28e528c19d28..b126fab6c4e1 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -175,6 +175,7 @@ const char *vm_guest_mode_string(uint32_t i)
>  		[VM_MODE_P40V48_4K]	= "PA-bits:40,  VA-bits:48,  4K pages",
>  		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
>  		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
> +		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
>  	};
>  	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
>  		       "Missing new mode strings?");
> @@ -192,6 +193,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
>  	{ 40, 48,  0x1000, 12 },
>  	{ 40, 48, 0x10000, 16 },
>  	{  0,  0,  0x1000, 12 },
> +	{ 47, 64,  0x1000, 12 },
>  };
>  _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
>  	       "Missing new mode params?");
> @@ -277,6 +279,9 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
>  		TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
>  #endif
>  		break;
> +	case VM_MODE_P47V64_4K:
> +		vm->pgtable_levels = 5;
> +		break;
>  	default:
>  		TEST_FAIL("Unknown guest mode, mode: 0x%x", mode);
>  	}
> -- 
> 2.31.1
> 

Re: [PATCH v2] KVM: selftests: introduce P47V64 for s390x

[Paolo Bonzini]

On 08/06/21 14:39, Christian Borntraeger wrote:
> s390x can have up to 47bits of physical guest and 64bits of virtual
> address  bits. Add a new address mode to avoid errors of testcases
> going beyond 47bits.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
> v1->v2:
> - remove wrong comment
> - use 5 levels of page tables
>   tools/testing/selftests/kvm/include/kvm_util.h | 3 ++-
>   tools/testing/selftests/kvm/lib/kvm_util.c     | 5 +++++
>   2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index fcd8e3855111..b602552b1ed0 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -43,6 +43,7 @@ enum vm_guest_mode {
>   	VM_MODE_P40V48_4K,
>   	VM_MODE_P40V48_64K,
>   	VM_MODE_PXXV48_4K,	/* For 48bits VA but ANY bits PA */
> +	VM_MODE_P47V64_4K,
>   	NUM_VM_MODES,
>   };
>   
> @@ -60,7 +61,7 @@ enum vm_guest_mode {
>   
>   #elif defined(__s390x__)
>   
> -#define VM_MODE_DEFAULT			VM_MODE_P52V48_4K
> +#define VM_MODE_DEFAULT			VM_MODE_P47V64_4K
>   #define MIN_PAGE_SHIFT			12U
>   #define ptes_per_page(page_size)	((page_size) / 16)
>   
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 28e528c19d28..b126fab6c4e1 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -175,6 +175,7 @@ const char *vm_guest_mode_string(uint32_t i)
>   		[VM_MODE_P40V48_4K]	= "PA-bits:40,  VA-bits:48,  4K pages",
>   		[VM_MODE_P40V48_64K]	= "PA-bits:40,  VA-bits:48, 64K pages",
>   		[VM_MODE_PXXV48_4K]	= "PA-bits:ANY, VA-bits:48,  4K pages",
> +		[VM_MODE_P47V64_4K]	= "PA-bits:47,  VA-bits:64,  4K pages",
>   	};
>   	_Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
>   		       "Missing new mode strings?");
> @@ -192,6 +193,7 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
>   	{ 40, 48,  0x1000, 12 },
>   	{ 40, 48, 0x10000, 16 },
>   	{  0,  0,  0x1000, 12 },
> +	{ 47, 64,  0x1000, 12 },
>   };
>   _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
>   	       "Missing new mode params?");
> @@ -277,6 +279,9 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
>   		TEST_FAIL("VM_MODE_PXXV48_4K not supported on non-x86 platforms");
>   #endif
>   		break;
> +	case VM_MODE_P47V64_4K:
> +		vm->pgtable_levels = 5;
> +		break;
>   	default:
>   		TEST_FAIL("Unknown guest mode, mode: 0x%x", mode);
>   	}
> 

Queued, thanks.

Paolo