Hi, Bibo,
On Wed, Jun 19, 2024 at 4:09 PM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
>
> Currently page level selection about secondary mmu depends on memory
> slot and page level about host mmu. There will be problem if page level
> of secondary mmu is zero already. So page level selection should depend
> on the following three conditions.
> 1. Memslot is aligned for huge page and vm is not migrating.
> 2. Page level of host mmu is huge page also.
> 3. Page level of secondary mmu is suituable for huge page, it cannot
> be normal page since it is not supported to merge normal pages into
> huge page now.
>
> Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
> ---
> arch/loongarch/include/asm/kvm_mmu.h | 2 +-
> arch/loongarch/kvm/mmu.c | 16 +++++++++++++---
> 2 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/kvm_mmu.h b/arch/loongarch/include/asm/kvm_mmu.h
> index 099bafc6f797..d06ae0e0dde5 100644
> --- a/arch/loongarch/include/asm/kvm_mmu.h
> +++ b/arch/loongarch/include/asm/kvm_mmu.h
> @@ -55,7 +55,7 @@ static inline void kvm_set_pte(kvm_pte_t *ptep, kvm_pte_t val)
> static inline int kvm_pte_write(kvm_pte_t pte) { return pte & _PAGE_WRITE; }
> static inline int kvm_pte_dirty(kvm_pte_t pte) { return pte & _PAGE_DIRTY; }
> static inline int kvm_pte_young(kvm_pte_t pte) { return pte & _PAGE_ACCESSED; }
> -static inline int kvm_pte_huge(kvm_pte_t pte) { return pte & _PAGE_HUGE; }
> +static inline int kvm_pte_huge(kvm_pte_t pte) { return !!(pte & _PAGE_HUGE); }
Why do we need this change?
Huacai
>
> static inline kvm_pte_t kvm_pte_mkyoung(kvm_pte_t pte)
> {
> diff --git a/arch/loongarch/kvm/mmu.c b/arch/loongarch/kvm/mmu.c
> index 9e39d28fec35..c6351d13ca1b 100644
> --- a/arch/loongarch/kvm/mmu.c
> +++ b/arch/loongarch/kvm/mmu.c
> @@ -858,10 +858,20 @@ static int kvm_map_page(struct kvm_vcpu *vcpu, unsigned long gpa, bool write)
>
> /* Disable dirty logging on HugePages */
> level = 0;
> - if (!fault_supports_huge_mapping(memslot, hva, write)) {
> - level = 0;
> - } else {
> + if (fault_supports_huge_mapping(memslot, hva, write)) {
> + /* Check page level about host mmu*/
> level = host_pfn_mapping_level(kvm, gfn, memslot);
> + if (level == 1) {
> + /*
> + * Check page level about secondary mmu
> + * Disable hugepage if it is normal page on
> + * secondary mmu already
> + */
> + ptep = kvm_populate_gpa(kvm, NULL, gpa, 0);
> + if (ptep && !kvm_pte_huge(*ptep))
> + level = 0;
> + }
> +
> if (level == 1) {
> gfn = gfn & ~(PTRS_PER_PTE - 1);
> pfn = pfn & ~(PTRS_PER_PTE - 1);
> --
> 2.39.3
>
