diff mbox series

selftests: kvm: make allocation of extra memory take effect

Message ID 20210512043107.30076-1-zhenzhong.duan@intel.com
State Accepted
Commit 39fe2fc96694164723846fccf6caa42c3aee6ec4
Headers show
Series selftests: kvm: make allocation of extra memory take effect | expand

Commit Message

Zhenzhong Duan May 12, 2021, 4:31 a.m. UTC
The extra memory pages is missed to be allocated during VM creating.
perf_test_util and kvm_page_table_test use it to alloc extra memory
currently.

Fix it by adding extra_mem_pages to the total memory calculation before
allocate.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Paolo Bonzini May 24, 2021, 12:27 p.m. UTC | #1
On 12/05/21 06:31, Zhenzhong Duan wrote:
> vm_vaddr_alloc() setup GVA to GPA mapping page by page, then GPA may not be

> continuous if same memslot is used for data and page table allocation.

> 

> kvm_vm_elf_load() expects a continuous memory of GPA or else it need to

> read file data page by page. Fix it by adding a check in vm_vaddr_alloc()

> to ensure memory is allocated in a whole if same memslot is used for data

> and page table.

> 

> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

> ---

Why not do

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 7426163d448a..f362a066f37a 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1170,6 +1170,9 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
  	uint64_t pages = (sz >> vm->page_shift) + ((sz % vm->page_size) != 0);
  
  	virt_pgd_alloc(vm, pgd_memslot);
+	vm_paddr_t paddr = vm_phy_pages_alloc(vm, pages,
+					      KVM_UTIL_MIN_PFN * vm->page_size,
+					      data_memslot);
  
  	/*
  	 * Find an unused range of virtual page addresses of at least
@@ -1179,11 +1182,7 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
  
  	/* Map the virtual pages. */
  	for (vm_vaddr_t vaddr = vaddr_start; pages > 0;
-		pages--, vaddr += vm->page_size) {
-		vm_paddr_t paddr;
-
-		paddr = vm_phy_page_alloc(vm,
-				KVM_UTIL_MIN_PFN * vm->page_size, data_memslot);
+		pages--, vaddr += vm->page_size, paddr += vm->page_size) {
  
  		virt_pg_map(vm, vaddr, paddr, pgd_memslot);
  

instead?

Paolo
Zhenzhong Duan May 25, 2021, 8:43 a.m. UTC | #2
> -----Original Message-----

> From: Paolo Bonzini <pbonzini@redhat.com>

> Sent: Monday, May 24, 2021 8:28 PM

> To: Duan, Zhenzhong <zhenzhong.duan@intel.com>; linux-

> kernel@vger.kernel.org

> Cc: linux-kselftest@vger.kernel.org; kvm@vger.kernel.org; shuah@kernel.org

> Subject: Re: [PATCH] selftests: kvm: Fix a potential elf loading issue

> 

> On 12/05/21 06:31, Zhenzhong Duan wrote:

> > vm_vaddr_alloc() setup GVA to GPA mapping page by page, then GPA may

> > not be continuous if same memslot is used for data and page table

> allocation.

> >

> > kvm_vm_elf_load() expects a continuous memory of GPA or else it need

> > to read file data page by page. Fix it by adding a check in

> > vm_vaddr_alloc() to ensure memory is allocated in a whole if same

> > memslot is used for data and page table.

> >

> > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

> > ---

> Why not do

> 

> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c

> b/tools/testing/selftests/kvm/lib/kvm_util.c

> index 7426163d448a..f362a066f37a 100644

> --- a/tools/testing/selftests/kvm/lib/kvm_util.c

> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c

> @@ -1170,6 +1170,9 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm,

> size_t sz, vm_vaddr_t vaddr_min,

>   	uint64_t pages = (sz >> vm->page_shift) + ((sz % vm->page_size) != 0);

> 

>   	virt_pgd_alloc(vm, pgd_memslot);

> +	vm_paddr_t paddr = vm_phy_pages_alloc(vm, pages,

> +					      KVM_UTIL_MIN_PFN * vm-

> >page_size,

> +					      data_memslot);

> 

>   	/*

>   	 * Find an unused range of virtual page addresses of at least @@ -

> 1179,11 +1182,7 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm,

> size_t sz, vm_vaddr_t vaddr_min,

> 

>   	/* Map the virtual pages. */

>   	for (vm_vaddr_t vaddr = vaddr_start; pages > 0;

> -		pages--, vaddr += vm->page_size) {

> -		vm_paddr_t paddr;

> -

> -		paddr = vm_phy_page_alloc(vm,

> -				KVM_UTIL_MIN_PFN * vm->page_size,

> data_memslot);

> +		pages--, vaddr += vm->page_size, paddr += vm->page_size) {

> 

>   		virt_pg_map(vm, vaddr, paddr, pgd_memslot);

> 

> 

> instead?


Yes, this is better, thanks for fixing.

Regards
Zhenzhong
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index fc83f6c5902d..159f4d62241d 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -295,7 +295,7 @@  struct kvm_vm *vm_create_with_vcpus(enum vm_guest_mode mode, uint32_t nr_vcpus,
 	 */
 	uint64_t vcpu_pages = (DEFAULT_STACK_PGS + num_percpu_pages) * nr_vcpus;
 	uint64_t extra_pg_pages = (extra_mem_pages + vcpu_pages) / PTES_PER_MIN_PAGE * 2;
-	uint64_t pages = DEFAULT_GUEST_PHY_PAGES + vcpu_pages + extra_pg_pages;
+	uint64_t pages = DEFAULT_GUEST_PHY_PAGES + extra_mem_pages + vcpu_pages + extra_pg_pages;
 	struct kvm_vm *vm;
 	int i;