On Tue, Mar 02, 2021 at 12:45:18PM +1100, David Gibson wrote: > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > > index 45fd862ac128..38ce3f21b21f 100644 > > --- a/Documentation/virt/kvm/api.rst > > +++ b/Documentation/virt/kvm/api.rst > > @@ -6225,6 +6225,24 @@ KVM_RUN_BUS_LOCK flag is used to distinguish between > > them. > > This capability can be used to check / enable 2nd DAWR feature provided > > by POWER10 processor. > > > > +7.23 KVM_CAP_PPC_RPT_INVALIDATE > > +------------------------------ > > + > > +:Capability: KVM_CAP_PPC_RPT_INVALIDATE > > +:Architectures: ppc > > +:Type: vm > > + > > +This capability indicates that the kernel is capable of handling > > +H_RPT_INVALIDATE hcall. > > + > > +In order to enable the use of H_RPT_INVALIDATE in the guest, > > +user space might have to advertise it for the guest. For example, > > +IBM pSeries (sPAPR) guest starts using it if "hcall-rpt-invalidate" is > > +present in the "ibm,hypertas-functions" device-tree property. > > + > > +This capability is enabled for hypervisors on platforms like POWER9 > > +that support radix MMU. > > Does this mean that KVM will handle the hypercall, even if not > explicitly enabled by userspace (qemu)? That's generally not what we > want, since we need to allow qemu to set up backwards compatible > guests.
This capability only indicates that hypervisor supports the hcall. QEMU will check for this and conditionally enable the hcall (via KVM_CAP_PPC_ENABLE_HCALL ioctl). Enabling the hcall is conditional to cap-rpt-invalidate sPAPR machine capability being enabled by the user. Will post a followup QEMU patch shortly. Older QEMU patch can be found here: https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg00627.html > > > + > > 8. Other capabilities. > > ====================== > > > > diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h > > b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h > > index 8b33601cdb9d..a46fd37ad552 100644 > > --- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h > > +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h > > @@ -4,6 +4,10 @@ > > > > #include <asm/hvcall.h> > > > > +#define RIC_FLUSH_TLB 0 > > +#define RIC_FLUSH_PWC 1 > > +#define RIC_FLUSH_ALL 2 > > + > > struct vm_area_struct; > > struct mm_struct; > > struct mmu_gather; > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h > > b/arch/powerpc/include/asm/kvm_book3s.h > > index 2f5f919f6cd3..a1515f94400e 100644 > > --- a/arch/powerpc/include/asm/kvm_book3s.h > > +++ b/arch/powerpc/include/asm/kvm_book3s.h > > @@ -305,6 +305,9 @@ void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, > > u64 dw1); > > void kvmhv_release_all_nested(struct kvm *kvm); > > long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu); > > long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu); > > +long kvmhv_h_rpti_nested(struct kvm_vcpu *vcpu, unsigned long lpid, > > + unsigned long type, unsigned long pg_sizes, > > + unsigned long start, unsigned long end); > > int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, > > u64 time_limit, unsigned long lpcr); > > void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr); > > diff --git a/arch/powerpc/include/asm/mmu_context.h > > b/arch/powerpc/include/asm/mmu_context.h > > index 652ce85f9410..820caf4e01b7 100644 > > --- a/arch/powerpc/include/asm/mmu_context.h > > +++ b/arch/powerpc/include/asm/mmu_context.h > > @@ -124,8 +124,19 @@ static inline bool need_extra_context(struct mm_struct > > *mm, unsigned long ea) > > > > #if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU) > > extern void radix_kvm_prefetch_workaround(struct mm_struct *mm); > > +void do_h_rpt_invalidate(unsigned long pid, unsigned long lpid, > > + unsigned long type, unsigned long page_size, > > + unsigned long psize, unsigned long start, > > + unsigned long end); > > #else > > static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { } > > +static inline void do_h_rpt_invalidate(unsigned long pid, > > + unsigned long lpid, > > + unsigned long type, > > + unsigned long page_size, > > + unsigned long psize, > > + unsigned long start, > > + unsigned long end) { } > > #endif > > > > extern void switch_cop(struct mm_struct *next); > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > > index 13bad6bf4c95..d83f006fc19d 100644 > > --- a/arch/powerpc/kvm/book3s_hv.c > > +++ b/arch/powerpc/kvm/book3s_hv.c > > @@ -921,6 +921,69 @@ static int kvmppc_get_yield_count(struct kvm_vcpu > > *vcpu) > > return yield_count; > > } > > > > +static void do_h_rpt_invalidate_prs(unsigned long pid, unsigned long lpid, > > + unsigned long type, unsigned long pg_sizes, > > + unsigned long start, unsigned long end) > > +{ > > + unsigned long psize; > > + struct mmu_psize_def *def; > > + > > + for (psize = 0; psize < MMU_PAGE_COUNT; psize++) { > > + def = &mmu_psize_defs[psize]; > > + if (pg_sizes & def->h_rpt_pgsize) > > + do_h_rpt_invalidate(pid, lpid, type, > > + (1UL << def->shift), psize, > > + start, end); > > + } > > +} > > + > > +static void kvmppc_nested_rpt_invalidate(struct kvm_vcpu *vcpu) > > +{ > > + do_h_rpt_invalidate_prs(kvmppc_get_gpr(vcpu, 4), > > + vcpu->arch.nested->shadow_lpid, > > + kvmppc_get_gpr(vcpu, 5), > > + kvmppc_get_gpr(vcpu, 6), > > + kvmppc_get_gpr(vcpu, 7), > > + kvmppc_get_gpr(vcpu, 8)); > > + kvmppc_set_gpr(vcpu, 3, H_SUCCESS); > > +} > > + > > +static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu, > > + unsigned long pid, unsigned long target, > > + unsigned long type, unsigned long pg_sizes, > > + unsigned long start, unsigned long end) > > +{ > > + if (!kvm_is_radix(vcpu->kvm)) > > + return H_UNSUPPORTED; > > + > > + /* > > + * For nested guests, this hcall is handled in > > + * L0. See kvmppc_handle_nested_exit() for details. > > + */ > > + if (kvmhv_on_pseries()) > > + return H_UNSUPPORTED; > > + > > + if (end < start) > > + return H_P5; > > + > > + if (type & H_RPTI_TYPE_NESTED) { > > + if (!nesting_enabled(vcpu->kvm)) > > + return H_FUNCTION; > > + > > + /* Support only cores as target */ > > + if (target != H_RPTI_TARGET_CMMU) > > + return H_P2; > > + > > IIUC, we'll hit this code path if an L1 calls this on behalf of an L2, Correct. > whereas we'll hit the nested exit code path going straight to > kvmhv_h_rpti_nested() if an L2 calls it on behalf of an L3. Is that > right? We will hit the nested exit code path when L2 calls it on behalf of L3. Looks like I am not handling this case (hcall issued by L2 on behalf of L3 for handling partition scoped translations) in the nested exit path. > > > + return kvmhv_h_rpti_nested(vcpu, pid, > > + (type & ~H_RPTI_TYPE_NESTED), > > + pg_sizes, start, end); > > + } > > + > > + do_h_rpt_invalidate_prs(pid, vcpu->kvm->arch.lpid, type, pg_sizes, > > + start, end); > > + return H_SUCCESS; > > +} > > + > > int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) > > { > > unsigned long req = kvmppc_get_gpr(vcpu, 3); > > @@ -1129,6 +1192,14 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) > > */ > > ret = kvmppc_h_svm_init_abort(vcpu->kvm); > > break; > > + case H_RPT_INVALIDATE: > > + ret = kvmppc_h_rpt_invalidate(vcpu, kvmppc_get_gpr(vcpu, 4), > > + kvmppc_get_gpr(vcpu, 5), > > + kvmppc_get_gpr(vcpu, 6), > > + kvmppc_get_gpr(vcpu, 7), > > + kvmppc_get_gpr(vcpu, 8), > > + kvmppc_get_gpr(vcpu, 9)); > > + break; > > > > default: > > return RESUME_HOST; > > @@ -1175,6 +1246,7 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd) > > case H_XIRR_X: > > #endif > > case H_PAGE_INIT: > > + case H_RPT_INVALIDATE: > > return 1; > > } > > > > @@ -1590,6 +1662,24 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu > > *vcpu) > > if (!xics_on_xive()) > > kvmppc_xics_rm_complete(vcpu, 0); > > break; > > + case BOOK3S_INTERRUPT_SYSCALL: > > + { > > + unsigned long req = kvmppc_get_gpr(vcpu, 3); > > + > > + /* > > + * The H_RPT_INVALIDATE hcalls issued by nested > > + * guests for process scoped invalidations when > > + * GTSE=0, are handled here in L0. > > + */ > > What if the L2 is not calling this for the GTSE=0 case, but on behalf > of an L3? That case would be for flushing partition scoped translations. I am realizing that I am not handling that case, but it should be handled here in the nested hcall exit path. Currently I am handling only the hcall requests for process scoped translations from nested guests here. > > > + if (req == H_RPT_INVALIDATE) { > > + kvmppc_nested_rpt_invalidate(vcpu); > > + r = RESUME_GUEST; > > + break; > > + } > > + > > + r = RESUME_HOST; > > + break; > > + } > > default: > > r = RESUME_HOST; > > break; > > diff --git a/arch/powerpc/kvm/book3s_hv_nested.c > > b/arch/powerpc/kvm/book3s_hv_nested.c > > index 0cd0e7aad588..ca43b2d38dce 100644 > > --- a/arch/powerpc/kvm/book3s_hv_nested.c > > +++ b/arch/powerpc/kvm/book3s_hv_nested.c > > @@ -1191,6 +1191,83 @@ long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu) > > return H_SUCCESS; > > } > > > > +static long do_tlb_invalidate_nested_tlb(struct kvm_vcpu *vcpu, > > + unsigned long lpid, > > + unsigned long page_size, > > + unsigned long ap, > > + unsigned long start, > > + unsigned long end) > > +{ > > + unsigned long addr = start; > > + int ret; > > + > > + do { > > + ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, > > + get_epn(addr)); > > + if (ret) > > + return ret; > > + addr += page_size; > > + } while (addr < end); > > + > > + return ret; > > +} > > + > > +static long do_tlb_invalidate_nested_all(struct kvm_vcpu *vcpu, > > + unsigned long lpid) > > +{ > > + struct kvm *kvm = vcpu->kvm; > > + struct kvm_nested_guest *gp; > > + > > + gp = kvmhv_get_nested(kvm, lpid, false); > > + if (gp) { > > + kvmhv_emulate_tlbie_lpid(vcpu, gp, RIC_FLUSH_ALL); > > + kvmhv_put_nested(gp); > > + } > > + return H_SUCCESS; > > +} > > + > > +long kvmhv_h_rpti_nested(struct kvm_vcpu *vcpu, unsigned long lpid, > > + unsigned long type, unsigned long pg_sizes, > > + unsigned long start, unsigned long end) > > +{ > > + struct kvm_nested_guest *gp; > > + long ret; > > + unsigned long psize, ap; > > + > > + /* > > + * If L2 lpid isn't valid, we need to return H_PARAMETER. > > + * > > + * However, nested KVM issues a L2 lpid flush call when creating > > + * partition table entries for L2. This happens even before the > > + * corresponding shadow lpid is created in HV which happens in > > + * H_ENTER_NESTED call. Since we can't differentiate this case from > > + * the invalid case, we ignore such flush requests and return success. > > + */ > > What if this is being called on behalf of an L3 or deeper? Do we need > something to do a translation from L3 to L2 addresses? I am not sure, I will have to check if gp->shadow_lpid points to correct nested LPID in all the cases. > > > + gp = kvmhv_find_nested(vcpu->kvm, lpid); > > + if (!gp) > > + return H_SUCCESS; Regards, Bharata.
