On 4/24/23 4:27 AM, Ricardo Koller wrote:
On Mon, Apr 17, 2023 at 03:04:47PM +0800, Gavin Shan wrote:
On 4/9/23 2:29 PM, Ricardo Koller wrote:
Add a capability for userspace to specify the eager split chunk size.
The chunk size specifies how many pages to break at a time, using a
single allocation. Bigger the chunk size, more pages need to be
allocated ahead of time.
Suggested-by: Oliver Upton <oliver.upton@xxxxxxxxx>
Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
---
Documentation/virt/kvm/api.rst | 28 ++++++++++++++++++++++++++
arch/arm64/include/asm/kvm_host.h | 15 ++++++++++++++
arch/arm64/include/asm/kvm_pgtable.h | 18 +++++++++++++++++
arch/arm64/kvm/arm.c | 30 ++++++++++++++++++++++++++++
arch/arm64/kvm/mmu.c | 3 +++
include/uapi/linux/kvm.h | 2 ++
6 files changed, 96 insertions(+)
With the following comments addressed:
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
[...]
+static inline bool kvm_is_block_size_supported(u64 size)
+{
+ bool is_power_of_two = !((size) & ((size)-1));
+
+ return is_power_of_two && (size & kvm_supported_block_sizes());
+}
+
IS_ALIGNED() maybe used here.
I've been trying to reuse some bitmap related function in the kernel,
like IS_ALIGNED(), but can't find anything. Or at least it doesn't occur
to me how.
kvm_is_block_size_supported() returns true if @size matches only one of
the bits set in kvm_supported_block_sizes(). For example, given these
supported sizes: 10000100001000.
kvm_is_block_size_supported(100000000) => true
kvm_is_block_size_supported(1100) => false
I was actually thinking of @is_power_of_two is replaced by IS_ALIGNED(),
For example:
static inline bool kvm_is_block_size_supported(u64 size)
{
return IS_ALIGNED(size, size) && (size & kvm_supported_block_sizes());
}
IS_ALIGNED() is defined in include/linux/align.h, as below. It's almost
similar to '((size) & ((size)-1))'
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
Thanks,
Gavin
