Re: [PATCH] KVM: Fix kvm_vcpu_map[_readonly]() function prototypes

From: Fang, Peter

Date: Tue Mar 31 2026 - 20:19:20 EST


On Tue, Mar 31, 2026 at 02:22:47AM +0000, Yosry Ahmed wrote:
>
> Most callers are converting a GPA to a GFN, I wonder if we should make
> the function take in a GPA instead? But then we'll need to the GPA not
> being aligned to a page boundary (either do gpa_to_gfn() in
> __kvm_vcpu_map() or fail if it's not aligned).

Thanks for the feedback!

Mapping guest memory into the host feels more like a GFN-based operation
to me. struct kvm_host_map is also designed around GFNs/PFNs so I think
using gfn_t in the function prototypes seems more natural. The caller
can handle the offset-in-page cases without creating a lot of complexity
in the APIs. But I'm happy to rework this if there's a desire to make
them more GPA-friendly.

>
> Not sure if that's a net improvement, mostly thinking out loud here.