From 2d34d1c3bbfd98da5e61c4caac3dda1366544aad Mon Sep 17 00:00:00 2001 From: Suraj Jitindar Singh Date: Fri, 22 Mar 2019 17:05:44 +1100 Subject: [PATCH] KVM: PPC: Book3S HV: Implement virtual mode H_PAGE_INIT handler Implement a virtual mode handler for the H_CALL H_PAGE_INIT which can be used to zero or copy a guest page. The page is defined to be 4k and must be 4k aligned. The in-kernel handler halves the time to handle this H_CALL compared to handling it in userspace for a radix guest. Signed-off-by: Suraj Jitindar Singh Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_hv.c | 80 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index b2b29d4..6a519b5 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -801,6 +801,80 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags, } } +/* Copy guest memory in place - must reside within a single memslot */ +static int kvmppc_copy_guest(struct kvm *kvm, gpa_t to, gpa_t from, + unsigned long len) +{ + struct kvm_memory_slot *to_memslot = NULL; + struct kvm_memory_slot *from_memslot = NULL; + unsigned long to_addr, from_addr; + int r; + + /* Get HPA for from address */ + from_memslot = gfn_to_memslot(kvm, from >> PAGE_SHIFT); + if (!from_memslot) + return -EFAULT; + if ((from + len) >= ((from_memslot->base_gfn + from_memslot->npages) + << PAGE_SHIFT)) + return -EINVAL; + from_addr = gfn_to_hva_memslot(from_memslot, from >> PAGE_SHIFT); + if (kvm_is_error_hva(from_addr)) + return -EFAULT; + from_addr |= (from & (PAGE_SIZE - 1)); + + /* Get HPA for to address */ + to_memslot = gfn_to_memslot(kvm, to >> PAGE_SHIFT); + if (!to_memslot) + return -EFAULT; + if ((to + len) >= ((to_memslot->base_gfn + to_memslot->npages) + << PAGE_SHIFT)) + return -EINVAL; + to_addr = gfn_to_hva_memslot(to_memslot, to >> PAGE_SHIFT); + if (kvm_is_error_hva(to_addr)) + return -EFAULT; + to_addr |= (to & (PAGE_SIZE - 1)); + + /* Perform copy */ + r = raw_copy_in_user((void __user *)to_addr, (void __user *)from_addr, + len); + if (r) + return -EFAULT; + mark_page_dirty(kvm, to >> PAGE_SHIFT); + return 0; +} + +static long kvmppc_h_page_init(struct kvm_vcpu *vcpu, unsigned long flags, + unsigned long dest, unsigned long src) +{ + u64 pg_sz = SZ_4K; /* 4K page size */ + u64 pg_mask = SZ_4K - 1; + int ret; + + /* Check for invalid flags (H_PAGE_SET_LOANED covers all CMO flags) */ + if (flags & ~(H_ICACHE_INVALIDATE | H_ICACHE_SYNCHRONIZE | + H_ZERO_PAGE | H_COPY_PAGE | H_PAGE_SET_LOANED)) + return H_PARAMETER; + + /* dest (and src if copy_page flag set) must be page aligned */ + if ((dest & pg_mask) || ((flags & H_COPY_PAGE) && (src & pg_mask))) + return H_PARAMETER; + + /* zero and/or copy the page as determined by the flags */ + if (flags & H_COPY_PAGE) { + ret = kvmppc_copy_guest(vcpu->kvm, dest, src, pg_sz); + if (ret < 0) + return H_PARAMETER; + } else if (flags & H_ZERO_PAGE) { + ret = kvm_clear_guest(vcpu->kvm, dest, pg_sz); + if (ret < 0) + return H_PARAMETER; + } + + /* We can ignore the remaining flags */ + + return H_SUCCESS; +} + static int kvm_arch_vcpu_yield_to(struct kvm_vcpu *target) { struct kvmppc_vcore *vcore = target->arch.vcore; @@ -1003,6 +1077,11 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) if (nesting_enabled(vcpu->kvm)) ret = kvmhv_copy_tofrom_guest_nested(vcpu); break; + case H_PAGE_INIT: + ret = kvmppc_h_page_init(vcpu, kvmppc_get_gpr(vcpu, 4), + kvmppc_get_gpr(vcpu, 5), + kvmppc_get_gpr(vcpu, 6)); + break; default: return RESUME_HOST; } @@ -1047,6 +1126,7 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd) case H_IPOLL: case H_XIRR_X: #endif + case H_PAGE_INIT: return 1; } -- 2.7.4