Re: [PATCH 09/15] KVM: selftests: Move per-VM GPA into perf_test_args
On Thu, Feb 11, 2021 at 7:58 AM Sean Christopherson 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.
Re: [PATCH 09/15] KVM: selftests: Move per-VM GPA into perf_test_args
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.
Re: [PATCH 09/15] KVM: selftests: Move per-VM GPA into perf_test_args
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
Re: [PATCH 09/15] KVM: selftests: Move per-VM GPA into perf_test_args
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.
Re: [PATCH 09/15] KVM: selftests: Move per-VM GPA into perf_test_args
On Wed, Feb 10, 2021 at 3:06 PM Sean Christopherson 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
Reviewed-by: Ben Gardon
> ---
> .../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 *
