On Thu, Jul 7, 2022 at 7:53 AM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
>
> The kvm_mmu_topup_memory_cache() always uses GFP_KERNEL_ACCOUNT for
> memory allocation which prevents it's use in atomic context. To address
> this limitation of kvm_mmu_topup_memory_cache(), we add gfp_custom flag
> in struct kvm_mmu_memory_cache. When the gfp_custom flag is set to some
> GFP_xyz flags, the kvm_mmu_topup_memory_cache() will use that instead of
> GFP_KERNEL_ACCOUNT.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> include/linux/kvm_types.h | 1 +
> virt/kvm/kvm_main.c | 4 +++-
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> index ac1ebb37a0ff..1dcfba68076a 100644
> --- a/include/linux/kvm_types.h
> +++ b/include/linux/kvm_types.h
> @@ -87,6 +87,7 @@ struct gfn_to_pfn_cache {
> struct kvm_mmu_memory_cache {
> int nobjs;
> gfp_t gfp_zero;
> + gfp_t gfp_custom;
> struct kmem_cache *kmem_cache;
> void *objects[KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE];
> };
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index a49df8988cd6..e3a6f7647474 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -386,7 +386,9 @@ int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
> if (mc->nobjs >= min)
> return 0;
> while (mc->nobjs < ARRAY_SIZE(mc->objects)) {
> - obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT);
> + obj = mmu_memory_cache_alloc_obj(mc, (mc->gfp_custom) ?
> + mc->gfp_custom :
> + GFP_KERNEL_ACCOUNT);
> if (!obj)
> return mc->nobjs >= min ? 0 : -ENOMEM;
> mc->objects[mc->nobjs++] = obj;
> --
> 2.34.1
>
Acked-by: Atish Patra <atishp@xxxxxxxxxxxx>
--
Regards,
Atish
