Re: [RFC PATCH v1 17/57] kvm: Remove PAGE_SIZE compile-time constant assumption

Ryan Roberts
2024-10-16T14:45:52Z

+ Paolo Bonzini

This was a rather tricky series to get the recipients correct for and my script
did not realize that "supporter" was a pseudonym for "maintainer" so you were
missed off the original post. Appologies!

More context in cover letter:
https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/

On 14/10/2024 11:58, Ryan Roberts wrote:
> To prepare for supporting boot-time page size selection, refactor code
> to remove assumptions about PAGE_SIZE being compile-time constant. Code
> intended to be equivalent when compile-time page size is active.
>
> Modify BUILD_BUG_ON() to compare with page size limit.
>
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
>
> ***NOTE***
> Any confused maintainers may want to read the cover note here for context:
> https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/
>
> virt/kvm/kvm_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index cb2b78e92910f..6c862bc41a672 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -4244,7 +4244,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
> goto vcpu_decrement;
> }
>
> - BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE);
> + BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE_MIN);
> page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
> if (!page) {
> r = -ENOMEM;