On Thu, Jul 7, 2022 at 7:53 AM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
>
> The in-kernel AIA IMSIC support requires on-demand mapping / unmapping
> of Guest IMSIC address to Host IMSIC guest files. To help achieve this,
> we add kvm_riscv_stage2_ioremap() and kvm_riscv_stage2_iounmap()
> functions. These new functions for updating G-stage page table mappings
> will be called in atomic context so we have special "in_atomic" parameter
> for this purpose.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/kvm_host.h | 5 +++++
> arch/riscv/kvm/mmu.c | 18 ++++++++++++++----
> 2 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 59a0cf2ca7b9..60c517e4d576 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -284,6 +284,11 @@ void kvm_riscv_hfence_vvma_gva(struct kvm *kvm,
> void kvm_riscv_hfence_vvma_all(struct kvm *kvm,
> unsigned long hbase, unsigned long hmask);
>
> +int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,
> + phys_addr_t hpa, unsigned long size,
> + bool writable, bool in_atomic);
> +void kvm_riscv_gstage_iounmap(struct kvm *kvm, gpa_t gpa,
> + unsigned long size);
> int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
> struct kvm_memory_slot *memslot,
> gpa_t gpa, unsigned long hva, bool is_write);
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index b75d4e200064..f7862ca4c4c6 100644
> --- a/arch/riscv/kvm/mmu.c
> +++ b/arch/riscv/kvm/mmu.c
> @@ -343,8 +343,9 @@ static void gstage_wp_memory_region(struct kvm *kvm, int slot)
> kvm_flush_remote_tlbs(kvm);
> }
>
> -static int gstage_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa,
> - unsigned long size, bool writable)
> +int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,
> + phys_addr_t hpa, unsigned long size,
> + bool writable, bool in_atomic)
> {
> pte_t pte;
> int ret = 0;
> @@ -353,6 +354,7 @@ static int gstage_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa,
> struct kvm_mmu_memory_cache pcache;
>
> memset(&pcache, 0, sizeof(pcache));
> + pcache.gfp_custom = (in_atomic) ? GFP_ATOMIC | __GFP_ACCOUNT : 0;
> pcache.gfp_zero = __GFP_ZERO;
>
> end = (gpa + size + PAGE_SIZE - 1) & PAGE_MASK;
> @@ -382,6 +384,13 @@ static int gstage_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa,
> return ret;
> }
>
> +void kvm_riscv_gstage_iounmap(struct kvm *kvm, gpa_t gpa, unsigned long size)
> +{
> + spin_lock(&kvm->mmu_lock);
> + gstage_unmap_range(kvm, gpa, size, false);
> + spin_unlock(&kvm->mmu_lock);
> +}
> +
> void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
> struct kvm_memory_slot *slot,
> gfn_t gfn_offset,
> @@ -517,8 +526,9 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
> goto out;
> }
>
> - ret = gstage_ioremap(kvm, gpa, pa,
> - vm_end - vm_start, writable);
> + ret = kvm_riscv_gstage_ioremap(kvm, gpa, pa,
> + vm_end - vm_start,
> + writable, false);
> if (ret)
> break;
> }
> --
> 2.34.1
>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
--
Regards,
Atish
