On Sat, Apr 08, 2023, Nicholas Piggin wrote:
> powerpc will require this to allocate MMU tables in guest memory that
> are aligned and larger than the base page size.
>
> Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> ---
> .../selftests/kvm/include/kvm_util_base.h | 2 +
> tools/testing/selftests/kvm/lib/kvm_util.c | 44 ++++++++++++-------
> 2 files changed, 29 insertions(+), 17 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
> index 16425da16861..8a27bd4111ff 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util_base.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
> @@ -679,6 +679,8 @@ const char *exit_reason_str(unsigned int exit_reason);
>
> vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
> uint32_t memslot);
> +vm_paddr_t vm_phy_pages_alloc_align(struct kvm_vm *vm, size_t num, size_t align,
> + vm_paddr_t paddr_min, uint32_t memslot);
> vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
> vm_paddr_t paddr_min, uint32_t memslot);
> vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 8ec20ac33de0..4f15bbbb8f5e 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -1898,6 +1898,7 @@ const char *exit_reason_str(unsigned int exit_reason)
> * Input Args:
> * vm - Virtual Machine
> * num - number of pages
> + * align - pages alignment
> * paddr_min - Physical address minimum
> * memslot - Memory region to allocate page from
> *
> @@ -1911,7 +1912,7 @@ const char *exit_reason_str(unsigned int exit_reason)
> * and their base address is returned. A TEST_ASSERT failure occurs if
> * not enough pages are available at or above paddr_min.
> */
> -vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
> +vm_paddr_t vm_phy_pages_alloc_align(struct kvm_vm *vm, size_t num, size_t align,
I'd prefer to use double underscores, even though they are imperfect, because
appending a single specifier always seems to result in the name becoming stale
sooner or later, e.g. when another param with a default is added.
And IIUC, PPC requires the page tables to be naturally aligned, so rather than
expose the inner helper and copy+paste the rather odd KVM_GUEST_PAGE_TABLE_MIN_PADDR
and vm->memslots[MEM_REGION_PT] stuff, what if we instead have vm_alloc_page_table()
deal with the alignment? And provide a PPC-specific wrapper so that other
architectures don't need to manually specify '1' page?
E.g.
---
.../selftests/kvm/include/kvm_util_base.h | 18 +++++++++++++++---
tools/testing/selftests/kvm/lib/kvm_util.c | 14 ++++++++------
.../selftests/kvm/lib/powerpc/processor.c | 8 ++------
3 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h
index f14a059f58fb..e52405c9fa8b 100644
--- a/tools/testing/selftests/kvm/include/kvm_util_base.h
+++ b/tools/testing/selftests/kvm/include/kvm_util_base.h
@@ -700,11 +700,23 @@ const char *exit_reason_str(unsigned int exit_reason);
vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
uint32_t memslot);
-vm_paddr_t vm_phy_pages_alloc_align(struct kvm_vm *vm, size_t num, size_t align,
- vm_paddr_t paddr_min, uint32_t memslot);
vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
vm_paddr_t paddr_min, uint32_t memslot);
-vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm);
+
+vm_paddr_t __vm_alloc_page_table(struct kvm_vm *vm, size_t nr_pages);
+
+/*
+ * PowerPC conditionally needs to allocate multiple pages for each page table,
+ * all other architectures consume exactly one page per table.
+ */
+#if defined(__powerpc64__
+#define vm_alloc_page_table __vm_alloc_page_table
+#else
+static inline vm_alloc_page_table(struct kvm_vm *vm)
+{
+ return __vm_alloc_page_table(vm, 1)
+}
+#endif
/*
* ____vm_create() does KVM_CREATE_VM and little else. __vm_create() also
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 70f792ba444c..ffd18afe9725 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1946,8 +1946,9 @@ const char *exit_reason_str(unsigned int exit_reason)
* and their base address is returned. A TEST_ASSERT failure occurs if
* not enough pages are available at or above paddr_min.
*/
-vm_paddr_t vm_phy_pages_alloc_align(struct kvm_vm *vm, size_t num, size_t align,
- vm_paddr_t paddr_min, uint32_t memslot)
+static vm_paddr_t __vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
+ size_t align, vm_paddr_t paddr_min,
+ uint32_t memslot)
{
struct userspace_mem_region *region;
sparsebit_idx_t pg, base;
@@ -1992,7 +1993,7 @@ vm_paddr_t vm_phy_pages_alloc_align(struct kvm_vm *vm, size_t num, size_t align,
vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num,
vm_paddr_t paddr_min, uint32_t memslot)
{
- return vm_phy_pages_alloc_align(vm, num, 1, paddr_min, memslot);
+ return __vm_phy_pages_alloc(vm, num, 1, paddr_min, memslot);
}
vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
@@ -2001,10 +2002,11 @@ vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min,
return vm_phy_pages_alloc(vm, 1, paddr_min, memslot);
}
-vm_paddr_t vm_alloc_page_table(struct kvm_vm *vm)
+vm_paddr_t __vm_alloc_page_table(struct kvm_vm *vm)
{
- return vm_phy_page_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR,
- vm->memslots[MEM_REGION_PT]);
+ return __vm_phy_pages_alloc(vm, KVM_GUEST_PAGE_TABLE_MIN_PADDR,
+ nr_pages, nr_pages,
+ vm->memslots[MEM_REGION_PT]);
}
/*
diff --git a/tools/testing/selftests/kvm/lib/powerpc/processor.c b/tools/testing/selftests/kvm/lib/powerpc/processor.c
index 7052ce9b5029..57d64d281467 100644
--- a/tools/testing/selftests/kvm/lib/powerpc/processor.c
+++ b/tools/testing/selftests/kvm/lib/powerpc/processor.c
@@ -44,9 +44,7 @@ void virt_arch_pgd_alloc(struct kvm_vm *vm)
pgd_pages = (1UL << (RADIX_PGD_INDEX_SIZE + 3)) >> vm->page_shift;
if (!pgd_pages)
pgd_pages = 1;
- pgtb = vm_phy_pages_alloc_align(vm, pgd_pages, pgd_pages,
- KVM_GUEST_PAGE_TABLE_MIN_PADDR,
- vm->memslots[MEM_REGION_PT]);
+ pt = vm_alloc_page_table(vm, pgd_pages);
vm->pgd = pgtb;
/* Set the base page directory in the proc table */
@@ -168,9 +166,7 @@ void virt_arch_pg_map(struct kvm_vm *vm, uint64_t gva, uint64_t gpa)
pt_pages = (1ULL << (nls + 3)) >> vm->page_shift;
if (!pt_pages)
pt_pages = 1;
- pt = vm_phy_pages_alloc_align(vm, pt_pages, pt_pages,
- KVM_GUEST_PAGE_TABLE_MIN_PADDR,
- vm->memslots[MEM_REGION_PT]);
+ pt = vm_alloc_page_table(vm, pt_pages);
pde = PDE_VALID | nls | pt;
*pdep = cpu_to_be64(pde);
}
base-commit: 15a281f5c83f34d4d1808e5f790403b0770c5e78
--
