On Wed, Jul 19, 2023, Yuan Yao wrote:

On Tue, Jul 18, 2023 at 04:44:50PM -0700, Sean Christopherson wrote:

quoted

From: Chao Peng <redacted>

This new KVM exit allows userspace to handle memory-related errors. It
indicates an error happens in KVM at guest memory range [gpa, gpa+size).
The flags includes additional information for userspace to handle the
error. Currently bit 0 is defined as 'private memory' where '1'
indicates error happens due to private memory access and '0' indicates
error happens due to shared memory access.

Now it's bit 3:

Yeah, I need to update (or write) a lot of changelogs.

#define KVM_MEMORY_EXIT_FLAG_PRIVATE (1ULL << 3)

I remember some other attributes were introduced in v10 yet:

#define KVM_MEMORY_ATTRIBUTE_READ              (1ULL << 0)
#define KVM_MEMORY_ATTRIBUTE_WRITE             (1ULL << 1)
#define KVM_MEMORY_ATTRIBUTE_EXECUTE           (1ULL << 2)
#define KVM_MEMORY_ATTRIBUTE_PRIVATE           (1ULL << 3)

So KVM_MEMORY_EXIT_FLAG_PRIVATE changed to bit 3 due to above things,
or other reason ? (Sorry I didn't follow v10 too much before).

Yep, I want to reserve space for the RWX bits.