[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2/2] x86/HVM: use available linear->phys translations in REP MOVS/STOS handling
> -----Original Message----- > From: Jan Beulich [mailto:JBeulich@xxxxxxxx] > Sent: 08 June 2016 14:10 > To: xen-devel > Cc: Paul Durrant > Subject: [PATCH 2/2] x86/HVM: use available linear->phys translations in REP > MOVS/STOS handling > > If we have the translation result available already, we should also use > is here. In my tests with Linux guests this eliminates all calls to > hvmemul_linear_to_phys() out of the two functions being changed. > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Paul Durrant <paul.durrant@xxxxxxxxxx> > > --- a/xen/arch/x86/hvm/emulate.c > +++ b/xen/arch/x86/hvm/emulate.c > @@ -1156,6 +1156,7 @@ static int hvmemul_rep_movs( > { > struct hvm_emulate_ctxt *hvmemul_ctxt = > container_of(ctxt, struct hvm_emulate_ctxt, ctxt); > + struct hvm_vcpu_io *vio = ¤t->arch.hvm_vcpu.hvm_io; > unsigned long saddr, daddr, bytes; > paddr_t sgpa, dgpa; > uint32_t pfec = PFEC_page_present; > @@ -1178,16 +1179,43 @@ static int hvmemul_rep_movs( > if ( hvmemul_ctxt->seg_reg[x86_seg_ss].attr.fields.dpl == 3 ) > pfec |= PFEC_user_mode; > > - rc = hvmemul_linear_to_phys( > - saddr, &sgpa, bytes_per_rep, reps, pfec, hvmemul_ctxt); > - if ( rc != X86EMUL_OKAY ) > - return rc; > + bytes = PAGE_SIZE - (saddr & ~PAGE_MASK); > + if ( vio->mmio_access.read_access && > + (vio->mmio_gva == (saddr & PAGE_MASK)) && > + bytes >= bytes_per_rep ) > + { > + sgpa = pfn_to_paddr(vio->mmio_gpfn) | (saddr & ~PAGE_MASK); > + if ( *reps * bytes_per_rep > bytes ) > + *reps = bytes / bytes_per_rep; > + } > + else > + { > + rc = hvmemul_linear_to_phys(saddr, &sgpa, bytes_per_rep, reps, pfec, > + hvmemul_ctxt); > + if ( rc != X86EMUL_OKAY ) > + return rc; > > - rc = hvmemul_linear_to_phys( > - daddr, &dgpa, bytes_per_rep, reps, > - pfec | PFEC_write_access, hvmemul_ctxt); > - if ( rc != X86EMUL_OKAY ) > - return rc; > + latch_linear_to_phys(vio, saddr, sgpa, 0); > + } > + > + bytes = PAGE_SIZE - (daddr & ~PAGE_MASK); > + if ( vio->mmio_access.write_access && > + (vio->mmio_gva == (daddr & PAGE_MASK)) && > + bytes >= bytes_per_rep ) > + { > + dgpa = pfn_to_paddr(vio->mmio_gpfn) | (daddr & ~PAGE_MASK); > + if ( *reps * bytes_per_rep > bytes ) > + *reps = bytes / bytes_per_rep; > + } > + else > + { > + rc = hvmemul_linear_to_phys(daddr, &dgpa, bytes_per_rep, reps, > + pfec | PFEC_write_access, hvmemul_ctxt); > + if ( rc != X86EMUL_OKAY ) > + return rc; > + > + latch_linear_to_phys(vio, daddr, dgpa, 1); > + } > > /* Check for MMIO ops */ > (void) get_gfn_query_unlocked(current->domain, sgpa >> PAGE_SHIFT, > &sp2mt); > @@ -1279,25 +1307,40 @@ static int hvmemul_rep_stos( > { > struct hvm_emulate_ctxt *hvmemul_ctxt = > container_of(ctxt, struct hvm_emulate_ctxt, ctxt); > - unsigned long addr; > + struct hvm_vcpu_io *vio = ¤t->arch.hvm_vcpu.hvm_io; > + unsigned long addr, bytes; > paddr_t gpa; > p2m_type_t p2mt; > bool_t df = !!(ctxt->regs->eflags & X86_EFLAGS_DF); > int rc = hvmemul_virtual_to_linear(seg, offset, bytes_per_rep, reps, > hvm_access_write, hvmemul_ctxt, > &addr); > > - if ( rc == X86EMUL_OKAY ) > + if ( rc != X86EMUL_OKAY ) > + return rc; > + > + bytes = PAGE_SIZE - (addr & ~PAGE_MASK); > + if ( vio->mmio_access.write_access && > + (vio->mmio_gva == (addr & PAGE_MASK)) && > + bytes >= bytes_per_rep ) > + { > + gpa = pfn_to_paddr(vio->mmio_gpfn) | (addr & ~PAGE_MASK); > + if ( *reps * bytes_per_rep > bytes ) > + *reps = bytes / bytes_per_rep; > + } > + else > { > uint32_t pfec = PFEC_page_present | PFEC_write_access; > > if ( hvmemul_ctxt->seg_reg[x86_seg_ss].attr.fields.dpl == 3 ) > pfec |= PFEC_user_mode; > > - rc = hvmemul_linear_to_phys( > - addr, &gpa, bytes_per_rep, reps, pfec, hvmemul_ctxt); > + rc = hvmemul_linear_to_phys(addr, &gpa, bytes_per_rep, reps, pfec, > + hvmemul_ctxt); > + if ( rc != X86EMUL_OKAY ) > + return rc; > + > + latch_linear_to_phys(vio, addr, gpa, 1); > } > - if ( rc != X86EMUL_OKAY ) > - return rc; > > /* Check for MMIO op */ > (void)get_gfn_query_unlocked(current->domain, gpa >> PAGE_SHIFT, > &p2mt); > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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