diff mbox series

[09/15] KVM: selftests: Move per-VM GPA into perf_test_args

Message ID 20210210230625.550939-10-seanjc@google.com (mailing list archive)
State New, archived
Headers show
Series VM: selftests: Hugepage fixes and cleanups | expand

Commit Message

Sean Christopherson Feb. 10, 2021, 11:06 p.m. UTC
Move the per-VM GPA into perf_test_args instead of storing it as a
separate global variable.  It's not obvious that guest_test_phys_mem
holds a GPA, nor that it's connected/coupled with per_vcpu->gpa.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../selftests/kvm/include/perf_test_util.h    |  8 +-----
 .../selftests/kvm/lib/perf_test_util.c        | 28 ++++++++-----------
 .../kvm/memslot_modification_stress_test.c    |  2 +-
 3 files changed, 13 insertions(+), 25 deletions(-)

Comments

Ben Gardon Feb. 11, 2021, 1:22 a.m. UTC | #1
On Wed, Feb 10, 2021 at 3:06 PM Sean Christopherson <seanjc@google.com> wrote:
>
> Move the per-VM GPA into perf_test_args instead of storing it as a
> separate global variable.  It's not obvious that guest_test_phys_mem
> holds a GPA, nor that it's connected/coupled with per_vcpu->gpa.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

Reviewed-by: Ben Gardon <bgardon@google.com>

> ---
>  .../selftests/kvm/include/perf_test_util.h    |  8 +-----
>  .../selftests/kvm/lib/perf_test_util.c        | 28 ++++++++-----------
>  .../kvm/memslot_modification_stress_test.c    |  2 +-
>  3 files changed, 13 insertions(+), 25 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h
> index 4d53238b139f..cccf1c44bddb 100644
> --- a/tools/testing/selftests/kvm/include/perf_test_util.h
> +++ b/tools/testing/selftests/kvm/include/perf_test_util.h
> @@ -29,6 +29,7 @@ struct perf_test_vcpu_args {
>  struct perf_test_args {
>         struct kvm_vm *vm;
>         uint64_t host_page_size;
> +       uint64_t gpa;
>         uint64_t guest_page_size;
>         int wr_fract;
>
> @@ -37,13 +38,6 @@ struct perf_test_args {
>
>  extern struct perf_test_args perf_test_args;
>
> -/*
> - * Guest physical memory offset of the testing memory slot.
> - * This will be set to the topmost valid physical address minus
> - * the test memory size.
> - */
> -extern uint64_t guest_test_phys_mem;
> -
>  struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
>                                    uint64_t vcpu_memory_bytes,
>                                    enum vm_mem_backing_src_type backing_src);
> diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
> index f22ce1836547..03f125236021 100644
> --- a/tools/testing/selftests/kvm/lib/perf_test_util.c
> +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
> @@ -9,8 +9,6 @@
>
>  struct perf_test_args perf_test_args;
>
> -uint64_t guest_test_phys_mem;
> -
>  /*
>   * Guest virtual memory offset of the testing memory slot.
>   * Must not conflict with identity mapped test code.
> @@ -87,29 +85,25 @@ 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_num_pages, vm_get_max_gfn(vm), vcpus,
> -                   vcpu_memory_bytes);
> +                   guest_num_pages, vm_get_max_gfn(vm), vcpus, vcpu_memory_bytes);
>
> -       guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
> -                             pta->guest_page_size;
> -       guest_test_phys_mem &= ~(pta->host_page_size - 1);
> +       pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size;
> +       pta->gpa &= ~(pta->host_page_size - 1);

Also not related to this patch, but another case for align.

>         if (backing_src == VM_MEM_SRC_ANONYMOUS_THP ||
>             backing_src == VM_MEM_SRC_ANONYMOUS_HUGETLB)
> -               guest_test_phys_mem &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> -
> +               pta->gpa &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);

also align

>  #ifdef __s390x__
>         /* Align to 1M (segment size) */
> -       guest_test_phys_mem &= ~((1 << 20) - 1);
> +       pta->gpa &= ~((1 << 20) - 1);

And here again (oof)

>  #endif
> -       pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
> +       pr_info("guest physical test memory offset: 0x%lx\n", pta->gpa);
>
>         /* Add an extra memory slot for testing */
> -       vm_userspace_mem_region_add(vm, backing_src, guest_test_phys_mem,
> -                                   PERF_TEST_MEM_SLOT_INDEX,
> -                                   guest_num_pages, 0);
> +       vm_userspace_mem_region_add(vm, backing_src, pta->gpa,
> +                                   PERF_TEST_MEM_SLOT_INDEX, guest_num_pages, 0);
>
>         /* Do mapping for the demand paging memory slot */
> -       virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
> +       virt_map(vm, guest_test_virt_mem, pta->gpa, guest_num_pages, 0);
>
>         ucall_init(vm, NULL);
>
> @@ -139,13 +133,13 @@ void perf_test_setup_vcpus(struct kvm_vm *vm, int vcpus,
>                                          (vcpu_id * vcpu_memory_bytes);
>                         vcpu_args->pages = vcpu_memory_bytes /
>                                            pta->guest_page_size;
> -                       vcpu_args->gpa = guest_test_phys_mem +
> +                       vcpu_args->gpa = pta->gpa +
>                                          (vcpu_id * vcpu_memory_bytes);
>                 } else {
>                         vcpu_args->gva = guest_test_virt_mem;
>                         vcpu_args->pages = (vcpus * vcpu_memory_bytes) /
>                                            pta->guest_page_size;
> -                       vcpu_args->gpa = guest_test_phys_mem;
> +                       vcpu_args->gpa = pta->gpa;
>                 }
>
>                 pr_debug("Added VCPU %d with test mem gpa [%lx, %lx)\n",
> diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
> index 6096bf0a5b34..569bb1f55bdf 100644
> --- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c
> +++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
> @@ -121,7 +121,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
>
>         add_remove_memslot(vm, p->memslot_modification_delay,
>                            p->nr_memslot_modifications,
> -                          guest_test_phys_mem +
> +                          perf_test_args.gpa +
>                            (guest_percpu_mem_size * nr_vcpus) +
>                            perf_test_args.host_page_size +
>                            perf_test_args.guest_page_size);
> --
> 2.30.0.478.g8a0d178c01-goog
>
Sean Christopherson Feb. 11, 2021, 1:56 a.m. UTC | #2
On Wed, Feb 10, 2021, Ben Gardon wrote:
> > diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
> > index f22ce1836547..03f125236021 100644
> > --- a/tools/testing/selftests/kvm/lib/perf_test_util.c
> > +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
> > @@ -9,8 +9,6 @@
> >
> >  struct perf_test_args perf_test_args;
> >
> > -uint64_t guest_test_phys_mem;
> > -
> >  /*
> >   * Guest virtual memory offset of the testing memory slot.
> >   * Must not conflict with identity mapped test code.
> > @@ -87,29 +85,25 @@ 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_num_pages, vm_get_max_gfn(vm), vcpus,
> > -                   vcpu_memory_bytes);
> > +                   guest_num_pages, vm_get_max_gfn(vm), vcpus, vcpu_memory_bytes);
> >
> > -       guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
> > -                             pta->guest_page_size;
> > -       guest_test_phys_mem &= ~(pta->host_page_size - 1);
> > +       pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size;
> > +       pta->gpa &= ~(pta->host_page_size - 1);
> 
> Also not related to this patch, but another case for align.
> 
> >         if (backing_src == VM_MEM_SRC_ANONYMOUS_THP ||
> >             backing_src == VM_MEM_SRC_ANONYMOUS_HUGETLB)
> > -               guest_test_phys_mem &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> > -
> > +               pta->gpa &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> 
> also align
> 
> >  #ifdef __s390x__
> >         /* Align to 1M (segment size) */
> > -       guest_test_phys_mem &= ~((1 << 20) - 1);
> > +       pta->gpa &= ~((1 << 20) - 1);
> 
> And here again (oof)

Yep, I'll fix all these and the align() comment in v2.
Paolo Bonzini Feb. 11, 2021, 1:12 p.m. UTC | #3
On 11/02/21 02:56, Sean Christopherson wrote:
>>> +       pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size;
>>> +       pta->gpa &= ~(pta->host_page_size - 1);
>> Also not related to this patch, but another case for align.
>>
>>>          if (backing_src == VM_MEM_SRC_ANONYMOUS_THP ||
>>>              backing_src == VM_MEM_SRC_ANONYMOUS_HUGETLB)
>>> -               guest_test_phys_mem &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
>>> -
>>> +               pta->gpa &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
>> also align
>>
>>>   #ifdef __s390x__
>>>          /* Align to 1M (segment size) */
>>> -       guest_test_phys_mem &= ~((1 << 20) - 1);
>>> +       pta->gpa &= ~((1 << 20) - 1);
>> And here again (oof)
> 
> Yep, I'll fix all these and the align() comment in v2.

This is not exactly align in fact; it is x & ~y rather than (x + y) & 
~y.  Are you going to introduce a round-down macro or is it a bug?  (I 
am lazy...).

Paolo
Sean Christopherson Feb. 11, 2021, 3:57 p.m. UTC | #4
On Thu, Feb 11, 2021, Paolo Bonzini wrote:
> On 11/02/21 02:56, Sean Christopherson wrote:
> > > > +       pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size;
> > > > +       pta->gpa &= ~(pta->host_page_size - 1);
> > > Also not related to this patch, but another case for align.
> > > 
> > > >          if (backing_src == VM_MEM_SRC_ANONYMOUS_THP ||
> > > >              backing_src == VM_MEM_SRC_ANONYMOUS_HUGETLB)
> > > > -               guest_test_phys_mem &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> > > > -
> > > > +               pta->gpa &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> > > also align
> > > 
> > > >   #ifdef __s390x__
> > > >          /* Align to 1M (segment size) */
> > > > -       guest_test_phys_mem &= ~((1 << 20) - 1);
> > > > +       pta->gpa &= ~((1 << 20) - 1);
> > > And here again (oof)
> > 
> > Yep, I'll fix all these and the align() comment in v2.
> 
> This is not exactly align in fact; it is x & ~y rather than (x + y) & ~y.
> Are you going to introduce a round-down macro or is it a bug?  (I am
> lazy...).

Good question.  I, too, was lazy.  I didn't look at the guts of align() when I
moved it, and I didn't look closely at Ben's suggestion.  I'll take a closer
look today and make sure everything is doing what it's supposed to do.
Ben Gardon Feb. 11, 2021, 5:33 p.m. UTC | #5
On Thu, Feb 11, 2021 at 7:58 AM Sean Christopherson <seanjc@google.com> wrote:
>
> On Thu, Feb 11, 2021, Paolo Bonzini wrote:
> > On 11/02/21 02:56, Sean Christopherson wrote:
> > > > > +       pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size;
> > > > > +       pta->gpa &= ~(pta->host_page_size - 1);
> > > > Also not related to this patch, but another case for align.
> > > >
> > > > >          if (backing_src == VM_MEM_SRC_ANONYMOUS_THP ||
> > > > >              backing_src == VM_MEM_SRC_ANONYMOUS_HUGETLB)
> > > > > -               guest_test_phys_mem &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> > > > > -
> > > > > +               pta->gpa &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
> > > > also align
> > > >
> > > > >   #ifdef __s390x__
> > > > >          /* Align to 1M (segment size) */
> > > > > -       guest_test_phys_mem &= ~((1 << 20) - 1);
> > > > > +       pta->gpa &= ~((1 << 20) - 1);
> > > > And here again (oof)
> > >
> > > Yep, I'll fix all these and the align() comment in v2.
> >
> > This is not exactly align in fact; it is x & ~y rather than (x + y) & ~y.
> > Are you going to introduce a round-down macro or is it a bug?  (I am
> > lazy...).
>
> Good question.  I, too, was lazy.  I didn't look at the guts of align() when I
> moved it, and I didn't look closely at Ben's suggestion.  I'll take a closer
> look today and make sure everything is doing what it's supposed to do.

Ooh, great point Paolo, that helper is indeed rounding up. My comment
in patch #2 was totally wrong. I forgot anyone would ever want to
round up. :/
My misunderstanding and the above use cases are probably good evidence
that it would be helpful to have both align_up and align_down helpers.
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h
index 4d53238b139f..cccf1c44bddb 100644
--- a/tools/testing/selftests/kvm/include/perf_test_util.h
+++ b/tools/testing/selftests/kvm/include/perf_test_util.h
@@ -29,6 +29,7 @@  struct perf_test_vcpu_args {
 struct perf_test_args {
 	struct kvm_vm *vm;
 	uint64_t host_page_size;
+	uint64_t gpa;
 	uint64_t guest_page_size;
 	int wr_fract;
 
@@ -37,13 +38,6 @@  struct perf_test_args {
 
 extern struct perf_test_args perf_test_args;
 
-/*
- * Guest physical memory offset of the testing memory slot.
- * This will be set to the topmost valid physical address minus
- * the test memory size.
- */
-extern uint64_t guest_test_phys_mem;
-
 struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus,
 				   uint64_t vcpu_memory_bytes,
 				   enum vm_mem_backing_src_type backing_src);
diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
index f22ce1836547..03f125236021 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
@@ -9,8 +9,6 @@ 
 
 struct perf_test_args perf_test_args;
 
-uint64_t guest_test_phys_mem;
-
 /*
  * Guest virtual memory offset of the testing memory slot.
  * Must not conflict with identity mapped test code.
@@ -87,29 +85,25 @@  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_num_pages, vm_get_max_gfn(vm), vcpus,
-		    vcpu_memory_bytes);
+		    guest_num_pages, vm_get_max_gfn(vm), vcpus, vcpu_memory_bytes);
 
-	guest_test_phys_mem = (vm_get_max_gfn(vm) - guest_num_pages) *
-			      pta->guest_page_size;
-	guest_test_phys_mem &= ~(pta->host_page_size - 1);
+	pta->gpa = (vm_get_max_gfn(vm) - guest_num_pages) * pta->guest_page_size;
+	pta->gpa &= ~(pta->host_page_size - 1);
 	if (backing_src == VM_MEM_SRC_ANONYMOUS_THP ||
 	    backing_src == VM_MEM_SRC_ANONYMOUS_HUGETLB)
-		guest_test_phys_mem &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
-
+		pta->gpa &= ~(KVM_UTIL_HUGEPAGE_ALIGNMENT - 1);
 #ifdef __s390x__
 	/* Align to 1M (segment size) */
-	guest_test_phys_mem &= ~((1 << 20) - 1);
+	pta->gpa &= ~((1 << 20) - 1);
 #endif
-	pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
+	pr_info("guest physical test memory offset: 0x%lx\n", pta->gpa);
 
 	/* Add an extra memory slot for testing */
-	vm_userspace_mem_region_add(vm, backing_src, guest_test_phys_mem,
-				    PERF_TEST_MEM_SLOT_INDEX,
-				    guest_num_pages, 0);
+	vm_userspace_mem_region_add(vm, backing_src, pta->gpa,
+				    PERF_TEST_MEM_SLOT_INDEX, guest_num_pages, 0);
 
 	/* Do mapping for the demand paging memory slot */
-	virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0);
+	virt_map(vm, guest_test_virt_mem, pta->gpa, guest_num_pages, 0);
 
 	ucall_init(vm, NULL);
 
@@ -139,13 +133,13 @@  void perf_test_setup_vcpus(struct kvm_vm *vm, int vcpus,
 					 (vcpu_id * vcpu_memory_bytes);
 			vcpu_args->pages = vcpu_memory_bytes /
 					   pta->guest_page_size;
-			vcpu_args->gpa = guest_test_phys_mem +
+			vcpu_args->gpa = pta->gpa +
 					 (vcpu_id * vcpu_memory_bytes);
 		} else {
 			vcpu_args->gva = guest_test_virt_mem;
 			vcpu_args->pages = (vcpus * vcpu_memory_bytes) /
 					   pta->guest_page_size;
-			vcpu_args->gpa = guest_test_phys_mem;
+			vcpu_args->gpa = pta->gpa;
 		}
 
 		pr_debug("Added VCPU %d with test mem gpa [%lx, %lx)\n",
diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
index 6096bf0a5b34..569bb1f55bdf 100644
--- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c
+++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c
@@ -121,7 +121,7 @@  static void run_test(enum vm_guest_mode mode, void *arg)
 
 	add_remove_memslot(vm, p->memslot_modification_delay,
 			   p->nr_memslot_modifications,
-			   guest_test_phys_mem +
+			   perf_test_args.gpa +
 			   (guest_percpu_mem_size * nr_vcpus) +
 			   perf_test_args.host_page_size +
 			   perf_test_args.guest_page_size);