From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joao Martins Subject: [PATCH RFC 27/39] KVM: x86/xen: grant copy support Date: Wed, 20 Feb 2019 20:15:57 +0000 Message-ID: <20190220201609.28290-28-joao.m.martins@oracle.com> References: <20190220201609.28290-1-joao.m.martins@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Ankur Arora , Boris Ostrovsky , Joao Martins , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <20190220201609.28290-1-joao.m.martins@oracle.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Copies from source grant reference to dest grant reference (or the other way around.) Signed-off-by: Joao Martins --- arch/x86/kvm/xen.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 8f06924e0dfa..fecc548b2f12 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -10,6 +10,7 @@ #include "ioapic.h" #include +#include #include #include #include @@ -1747,6 +1748,148 @@ static int shim_hcall_gntunmap(struct kvm_xen *xen, return 0; } +static unsigned long __kvm_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn) +{ + struct kvm_xen *xen = vcpu ? &vcpu->kvm->arch.xen : xen_shim; + unsigned long hva; + + if (xen->domid == 0) + return (unsigned long) page_to_virt(pfn_to_page(gfn)); + + hva = gfn_to_hva(vcpu->kvm, gfn); + if (unlikely(kvm_is_error_hva(hva))) + return 0; + + return hva; +} + +static int __kvm_gref_to_page(struct kvm_vcpu *vcpu, grant_ref_t ref, + domid_t domid, struct page **page, + int16_t *status) +{ + struct kvm_xen *source = vcpu ? &vcpu->kvm->arch.xen : xen_shim; + struct grant_entry_v1 *shah; + struct grant_entry_v1 **gt; + struct kvm *dest; + + dest = kvm_xen_find_vm(domid); + if (unlikely(!dest)) { + pr_err("gnttab: could not find domain %u\n", domid); + *status = GNTST_bad_domain; + return 0; + } + + if (unlikely(ref >= gnttab_entries(dest))) { + pr_err("gnttab: bad ref %u\n", ref); + *status = GNTST_bad_gntref; + return 0; + } + + gt = dest->arch.xen.gnttab.frames_v1; + shah = shared_entry(gt, ref); + if (unlikely(shah->domid != source->domid)) { + pr_err("gnttab: bad domain (%u != %u)\n", + shah->domid, source->domid); + *status = GNTST_bad_gntref; + return 0; + } + + (void) map_grant_nosleep(dest, shah->frame, 0, page, status); + + return 0; +} + +static int shim_hcall_gntcopy(struct kvm_vcpu *vcpu, + struct gnttab_copy *op) +{ + void *saddr = NULL, *daddr = NULL; + struct page *spage = NULL, *dpage = NULL; + unsigned long hva; + int err = -ENOSYS; + gfn_t gfn; + + if (!(op->flags & GNTCOPY_source_gref) && + (op->source.domid == DOMID_SELF)) { + gfn = op->source.u.gmfn; + hva = __kvm_gfn_to_hva(vcpu, gfn); + if (unlikely(!hva)) { + pr_err("gnttab: bad source gfn:%llx\n", gfn); + op->status = GNTST_general_error; + err = 0; + return 0; + } + + saddr = (void *) (((unsigned long) hva) + op->source.offset); + } else if (op->flags & GNTCOPY_source_gref) { + op->status = GNTST_okay; + if (__kvm_gref_to_page(vcpu, op->source.u.ref, + op->source.domid, &spage, &op->status)) + return -EFAULT; + + if (!spage || op->status != GNTST_okay) { + pr_err("gnttab: failed to get page for source gref:%x\n", + op->source.u.ref); + err = 0; + goto out; + } + + saddr = kmap(spage); + saddr = (void *) (((unsigned long) saddr) + op->source.offset); + } + + if (!(op->flags & GNTCOPY_dest_gref) && + (op->dest.domid == DOMID_SELF)) { + gfn = op->dest.u.gmfn; + hva = __kvm_gfn_to_hva(vcpu, gfn); + if (unlikely(!hva)) { + pr_err("gnttab: bad dest gfn:%llx\n", gfn); + op->status = GNTST_general_error; + err = 0; + return 0; + } + + daddr = (void *) (((unsigned long) hva) + op->dest.offset); + } else if (op->flags & GNTCOPY_dest_gref) { + op->status = GNTST_okay; + if (__kvm_gref_to_page(vcpu, op->dest.u.ref, + op->dest.domid, &dpage, &op->status)) + return -EFAULT; + + if (!dpage || op->status != GNTST_okay) { + pr_err("gnttab: failed to get page for dest gref:%x\n", + op->dest.u.ref); + err = 0; + goto out; + } + + daddr = kmap(dpage); + daddr = (void *) (((unsigned long) daddr) + op->dest.offset); + } + + if (unlikely(!daddr || !saddr)) { + op->status = GNTST_general_error; + err = 0; + goto out; + } + + memcpy(daddr, saddr, op->len); + + if (spage) + kunmap(spage); + if (dpage) + kunmap(dpage); + + + err = 0; + op->status = GNTST_okay; +out: + if (spage) + put_page(spage); + if (dpage) + put_page(dpage); + return err; +} + static int shim_hcall_gnttab(int op, void *p, int count) { int ret = -ENOSYS; @@ -1771,6 +1914,14 @@ static int shim_hcall_gnttab(int op, void *p, int count) ret = 0; break; } + case GNTTABOP_copy: { + struct gnttab_copy *op = p; + + for (i = 0; i < count; i++) + shim_hcall_gntcopy(NULL, op + i); + ret = 0; + break; + } default: pr_info("lcall-gnttab:op default=%d\n", op); break; -- 2.11.0