Hi, Bibo,
On Wed, Nov 13, 2024 at 11:17 AM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
>
> LoongArch KVM hypervisor supports two-level MMU, vpid index is used
> for stage1 MMU and vmid index is used for stage2 MMU.
>
> On 3A5000, vmid must be the same with vpid. On 3A6000 platform vmid
> may separate from vpid. If vcpu migrate to different physical CPUs,
> vpid need change however vmid can keep the same with old value. Also
> vmid index of the while VM machine on physical CPU the same, all vCPUs
> on the VM can share the same vmid index on one physical CPU.
>
> Here vmid index is added and it keeps the same with vpid still.
>
> Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
> ---
> arch/loongarch/include/asm/kvm_host.h | 3 +++
> arch/loongarch/kernel/asm-offsets.c | 1 +
> arch/loongarch/kvm/main.c | 1 +
> arch/loongarch/kvm/switch.S | 5 ++---
> arch/loongarch/kvm/tlb.c | 5 ++++-
> 5 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
> index d6bb72424027..6151c7c470d5 100644
> --- a/arch/loongarch/include/asm/kvm_host.h
> +++ b/arch/loongarch/include/asm/kvm_host.h
> @@ -166,6 +166,9 @@ struct kvm_vcpu_arch {
> unsigned long host_tp;
> unsigned long host_pgd;
>
> + /* vmid info for guest VM */
> + unsigned long vmid;
vmid is a member of kvm_vcpu_arch, no of kvm_arch?
> +
> /* Host CSRs are used when handling exits from guest */
> unsigned long badi;
> unsigned long badv;
> diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c
> index bee9f7a3108f..4e9a9311afd3 100644
> --- a/arch/loongarch/kernel/asm-offsets.c
> +++ b/arch/loongarch/kernel/asm-offsets.c
> @@ -307,6 +307,7 @@ static void __used output_kvm_defines(void)
> OFFSET(KVM_ARCH_HSP, kvm_vcpu_arch, host_sp);
> OFFSET(KVM_ARCH_HTP, kvm_vcpu_arch, host_tp);
> OFFSET(KVM_ARCH_HPGD, kvm_vcpu_arch, host_pgd);
> + OFFSET(KVM_ARCH_VMID, kvm_vcpu_arch, vmid);
> OFFSET(KVM_ARCH_HANDLE_EXIT, kvm_vcpu_arch, handle_exit);
> OFFSET(KVM_ARCH_HEENTRY, kvm_vcpu_arch, host_eentry);
> OFFSET(KVM_ARCH_GEENTRY, kvm_vcpu_arch, guest_eentry);
> diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
> index 27e9b94c0a0b..8c16bff80053 100644
> --- a/arch/loongarch/kvm/main.c
> +++ b/arch/loongarch/kvm/main.c
> @@ -212,6 +212,7 @@ static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
>
> context->vpid_cache = vpid;
> vcpu->arch.vpid = vpid;
I think vpid should also be:
vcpu->arch.vpid = vpid & vpid_mask;
Huacai
> + vcpu->arch.vmid = vcpu->arch.vpid & vpid_mask;
> }
>
> void kvm_check_vpid(struct kvm_vcpu *vcpu)
> diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S
> index 0c292f818492..2774343f64d3 100644
> --- a/arch/loongarch/kvm/switch.S
> +++ b/arch/loongarch/kvm/switch.S
> @@ -72,9 +72,8 @@
> ldx.d t0, t1, t0
> csrwr t0, LOONGARCH_CSR_PGDL
>
> - /* Mix GID and RID */
> - csrrd t1, LOONGARCH_CSR_GSTAT
> - bstrpick.w t1, t1, CSR_GSTAT_GID_SHIFT_END, CSR_GSTAT_GID_SHIFT
> + /* Set VMID for gpa --> hpa mapping */
> + ld.d t1, a2, KVM_ARCH_VMID
> csrrd t0, LOONGARCH_CSR_GTLBC
> bstrins.w t0, t1, CSR_GTLBC_TGID_SHIFT_END, CSR_GTLBC_TGID_SHIFT
> csrwr t0, LOONGARCH_CSR_GTLBC
> diff --git a/arch/loongarch/kvm/tlb.c b/arch/loongarch/kvm/tlb.c
> index ebdbe9264e9c..38daf936021d 100644
> --- a/arch/loongarch/kvm/tlb.c
> +++ b/arch/loongarch/kvm/tlb.c
> @@ -23,7 +23,10 @@ void kvm_flush_tlb_all(void)
>
> void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa)
> {
> + unsigned int vmid;
> +
> lockdep_assert_irqs_disabled();
> gpa &= (PAGE_MASK << 1);
> - invtlb(INVTLB_GID_ADDR, read_csr_gstat() & CSR_GSTAT_GID, gpa);
> + vmid = (vcpu->arch.vmid << CSR_GSTAT_GID_SHIFT) & CSR_GSTAT_GID;
> + invtlb(INVTLB_GID_ADDR, vmid, gpa);
> }
> --
> 2.39.3
>
