On Wed, Apr 20, 2022 at 4:25 AM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
>
> Latest QEMU supports G-stage Sv57x4 mode so this patch extends KVM
> RISC-V G-stage handling to detect and use Sv57x4 mode when available.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/csr.h | 1 +
> arch/riscv/kvm/main.c | 3 +++
> arch/riscv/kvm/mmu.c | 11 ++++++++++-
> 3 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
> index e935f27b10fd..cc40521e438b 100644
> --- a/arch/riscv/include/asm/csr.h
> +++ b/arch/riscv/include/asm/csr.h
> @@ -117,6 +117,7 @@
> #define HGATP_MODE_SV32X4 _AC(1, UL)
> #define HGATP_MODE_SV39X4 _AC(8, UL)
> #define HGATP_MODE_SV48X4 _AC(9, UL)
> +#define HGATP_MODE_SV57X4 _AC(10, UL)
>
> #define HGATP32_MODE_SHIFT 31
> #define HGATP32_VMID_SHIFT 22
> diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
> index c374dad82eee..1549205fe5fe 100644
> --- a/arch/riscv/kvm/main.c
> +++ b/arch/riscv/kvm/main.c
> @@ -105,6 +105,9 @@ int kvm_arch_init(void *opaque)
> case HGATP_MODE_SV48X4:
> str = "Sv48x4";
> break;
> + case HGATP_MODE_SV57X4:
> + str = "Sv57x4";
> + break;
> default:
> return -ENODEV;
> }
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index dc0520792e31..8823eb32dcde 100644
> --- a/arch/riscv/kvm/mmu.c
> +++ b/arch/riscv/kvm/mmu.c
> @@ -751,14 +751,23 @@ void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu)
> void kvm_riscv_gstage_mode_detect(void)
> {
> #ifdef CONFIG_64BIT
> + /* Try Sv57x4 G-stage mode */
> + csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
> + if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) {
> + gstage_mode = (HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT);
> + gstage_pgd_levels = 5;
> + goto skip_sv48x4_test;
> + }
> +
> /* Try Sv48x4 G-stage mode */
> csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
> if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) {
> gstage_mode = (HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT);
> gstage_pgd_levels = 4;
> }
> - csr_write(CSR_HGATP, 0);
> +skip_sv48x4_test:
>
> + csr_write(CSR_HGATP, 0);
> __kvm_riscv_hfence_gvma_all();
> #endif
> }
> --
> 2.25.1
>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
--
Regards,
Atish
