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 <[email protected]>
---
tools/testing/selftests/kvm/lib/kvm_util.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 159f4d62241d..6118a2f8906e 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1097,9 +1097,14 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
uint32_t data_memslot, uint32_t pgd_memslot)
{
uint64_t pages = (sz >> vm->page_shift) + ((sz % vm->page_size) != 0);
+ vm_paddr_t paddr_start = 0;
virt_pgd_alloc(vm, pgd_memslot);
+ if (data_memslot == pgd_memslot)
+ paddr_start = 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
* pages in length.
@@ -1111,8 +1116,12 @@ vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
pages--, vaddr += vm->page_size) {
vm_paddr_t paddr;
- paddr = vm_phy_page_alloc(vm,
- KVM_UTIL_MIN_PFN * vm->page_size, data_memslot);
+ if (paddr_start) {
+ paddr = paddr_start;
+ paddr_start += vm->page_size;
+ } else
+ paddr = vm_phy_page_alloc(vm,
+ KVM_UTIL_MIN_PFN * vm->page_size, data_memslot);
virt_pg_map(vm, vaddr, paddr, pgd_memslot);
--
2.25.1
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 <[email protected]>
> ---
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
> -----Original Message-----
> From: Paolo Bonzini <[email protected]>
> Sent: Monday, May 24, 2021 8:28 PM
> To: Duan, Zhenzhong <[email protected]>; linux-
> [email protected]
> Cc: [email protected]; [email protected]; [email protected]
> 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 <[email protected]>
> > ---
> 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