On Tue, Mar 02, 2021 at 10:28:53AM +0530, Bharata B Rao wrote: > 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. Ok. > 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. Ok. At the very least you need to detect and fail for that case. > > > > > + 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. > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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