From: Paul Durrant <Paul.Durrant@citrix.com> To: 'Alexandru Stefan ISAILA' <aisaila@bitdefender.com>, "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org> Cc: "tamas@tklengyel.com" <tamas@tklengyel.com>, Wei Liu <wei.liu2@citrix.com>, "rcojocaru@bitdefender.com" <rcojocaru@bitdefender.com>, Andrew Cooper <Andrew.Cooper3@citrix.com>, George Dunlap <George.Dunlap@citrix.com>, "jbeulich@suse.com" <jbeulich@suse.com>, Roger Pau Monne <roger.pau@citrix.com> Subject: Re: [PATCH v4 1/2] x86/emulate: Move hvmemul_linear_to_phys Date: Wed, 22 May 2019 13:13:38 +0000 [thread overview] Message-ID: <153d4f7da0a24805bb7112f6ff2beb80@AMSPEX02CL03.citrite.net> (raw) In-Reply-To: <20190520125454.14805-1-aisaila@bitdefender.com> > -----Original Message----- > From: Alexandru Stefan ISAILA [mailto:aisaila@bitdefender.com] > Sent: 20 May 2019 13:55 > To: xen-devel@lists.xenproject.org > Cc: Paul Durrant <Paul.Durrant@citrix.com>; jbeulich@suse.com; Andrew Cooper > <Andrew.Cooper3@citrix.com>; Wei Liu <wei.liu2@citrix.com>; Roger Pau Monne <roger.pau@citrix.com>; > rcojocaru@bitdefender.com; tamas@tklengyel.com; George Dunlap <George.Dunlap@citrix.com>; Alexandru > Stefan ISAILA <aisaila@bitdefender.com> > Subject: [PATCH v4 1/2] x86/emulate: Move hvmemul_linear_to_phys > > Thiis is done so hvmemul_linear_to_phys() can be called from > hvmemul_send_vm_event(). > > Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com> > --- > xen/arch/x86/hvm/emulate.c | 181 ++++++++++++++++++------------------- > 1 file changed, 90 insertions(+), 91 deletions(-) > > diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c > index 8659c89862..254ff6515d 100644 > --- a/xen/arch/x86/hvm/emulate.c > +++ b/xen/arch/x86/hvm/emulate.c > @@ -530,6 +530,95 @@ static int hvmemul_do_mmio_addr(paddr_t mmio_gpa, > return hvmemul_do_io_addr(1, mmio_gpa, reps, size, dir, df, ram_gpa); > } > I know this is code movement, but it would probably good to a do a bit of tidying... > +/* > + * Convert addr from linear to physical form, valid over the range > + * [addr, addr + *reps * bytes_per_rep]. *reps is adjusted according to > + * the valid computed range. It is always >0 when X86EMUL_OKAY is returned. > + * @pfec indicates the access checks to be performed during page-table walks. > + */ > +static int hvmemul_linear_to_phys( > + unsigned long addr, > + paddr_t *paddr, > + unsigned int bytes_per_rep, > + unsigned long *reps, > + uint32_t pfec, > + struct hvm_emulate_ctxt *hvmemul_ctxt) This can all be re-flowed since arg-per-line is not really canonical style. > +{ > + struct vcpu *curr = current; > + unsigned long pfn, npfn, done, todo, i, offset = addr & ~PAGE_MASK; > + int reverse; Looks like this should be bool. > + > + /* > + * Clip repetitions to a sensible maximum. This avoids extensive looping in > + * this function while still amortising the cost of I/O trap-and-emulate. > + */ > + *reps = min_t(unsigned long, *reps, 4096); > + > + /* With no paging it's easy: linear == physical. */ > + if ( !(curr->arch.hvm.guest_cr[0] & X86_CR0_PG) ) > + { > + *paddr = addr; > + return X86EMUL_OKAY; > + } > + > + /* Reverse mode if this is a backwards multi-iteration string operation. */ > + reverse = (hvmemul_ctxt->ctxt.regs->eflags & X86_EFLAGS_DF) && (*reps > 1); > + > + if ( reverse && ((PAGE_SIZE - offset) < bytes_per_rep) ) > + { > + /* Do page-straddling first iteration forwards via recursion. */ > + paddr_t _paddr; > + unsigned long one_rep = 1; > + int rc = hvmemul_linear_to_phys( > + addr, &_paddr, bytes_per_rep, &one_rep, pfec, hvmemul_ctxt); Blank line here. > + if ( rc != X86EMUL_OKAY ) > + return rc; > + pfn = _paddr >> PAGE_SHIFT; paddr_to_pfn() > + } > + else if ( (pfn = paging_gva_to_gfn(curr, addr, &pfec)) == gfn_x(INVALID_GFN) ) > + { > + if ( pfec & (PFEC_page_paged | PFEC_page_shared) ) > + return X86EMUL_RETRY; > + *reps = 0; > + x86_emul_pagefault(pfec, addr, &hvmemul_ctxt->ctxt); > + return X86EMUL_EXCEPTION; > + } > + > + done = reverse ? bytes_per_rep + offset : PAGE_SIZE - offset; > + todo = *reps * bytes_per_rep; > + for ( i = 1; done < todo; i++ ) > + { > + /* Get the next PFN in the range. */ > + addr += reverse ? -PAGE_SIZE : PAGE_SIZE; > + npfn = paging_gva_to_gfn(curr, addr, &pfec); > + > + /* Is it contiguous with the preceding PFNs? If not then we're done. */ > + if ( (npfn == gfn_x(INVALID_GFN)) || > + (npfn != (pfn + (reverse ? -i : i))) ) > + { > + if ( pfec & (PFEC_page_paged | PFEC_page_shared) ) > + return X86EMUL_RETRY; > + done /= bytes_per_rep; > + if ( done == 0 ) > + { > + ASSERT(!reverse); > + if ( npfn != gfn_x(INVALID_GFN) ) > + return X86EMUL_UNHANDLEABLE; > + *reps = 0; > + x86_emul_pagefault(pfec, addr & PAGE_MASK, &hvmemul_ctxt->ctxt); > + return X86EMUL_EXCEPTION; > + } > + *reps = done; > + break; > + } > + > + done += PAGE_SIZE; > + } > + > + *paddr = ((paddr_t)pfn << PAGE_SHIFT) | offset; pfn_to_paddr() and a blank line before the return. > + return X86EMUL_OKAY; > +} > + Thanks, Paul _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
From: Paul Durrant <Paul.Durrant@citrix.com> To: 'Alexandru Stefan ISAILA' <aisaila@bitdefender.com>, "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org> Cc: "tamas@tklengyel.com" <tamas@tklengyel.com>, Wei Liu <wei.liu2@citrix.com>, "rcojocaru@bitdefender.com" <rcojocaru@bitdefender.com>, Andrew Cooper <Andrew.Cooper3@citrix.com>, George Dunlap <George.Dunlap@citrix.com>, "jbeulich@suse.com" <jbeulich@suse.com>, Roger Pau Monne <roger.pau@citrix.com> Subject: Re: [Xen-devel] [PATCH v4 1/2] x86/emulate: Move hvmemul_linear_to_phys Date: Wed, 22 May 2019 13:13:38 +0000 [thread overview] Message-ID: <153d4f7da0a24805bb7112f6ff2beb80@AMSPEX02CL03.citrite.net> (raw) Message-ID: <20190522131338.AVzFYkrCXT0NYicPz0IltA3EnPI4loVAdpFlJSgNvZ8@z> (raw) In-Reply-To: <20190520125454.14805-1-aisaila@bitdefender.com> > -----Original Message----- > From: Alexandru Stefan ISAILA [mailto:aisaila@bitdefender.com] > Sent: 20 May 2019 13:55 > To: xen-devel@lists.xenproject.org > Cc: Paul Durrant <Paul.Durrant@citrix.com>; jbeulich@suse.com; Andrew Cooper > <Andrew.Cooper3@citrix.com>; Wei Liu <wei.liu2@citrix.com>; Roger Pau Monne <roger.pau@citrix.com>; > rcojocaru@bitdefender.com; tamas@tklengyel.com; George Dunlap <George.Dunlap@citrix.com>; Alexandru > Stefan ISAILA <aisaila@bitdefender.com> > Subject: [PATCH v4 1/2] x86/emulate: Move hvmemul_linear_to_phys > > Thiis is done so hvmemul_linear_to_phys() can be called from > hvmemul_send_vm_event(). > > Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com> > --- > xen/arch/x86/hvm/emulate.c | 181 ++++++++++++++++++------------------- > 1 file changed, 90 insertions(+), 91 deletions(-) > > diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c > index 8659c89862..254ff6515d 100644 > --- a/xen/arch/x86/hvm/emulate.c > +++ b/xen/arch/x86/hvm/emulate.c > @@ -530,6 +530,95 @@ static int hvmemul_do_mmio_addr(paddr_t mmio_gpa, > return hvmemul_do_io_addr(1, mmio_gpa, reps, size, dir, df, ram_gpa); > } > I know this is code movement, but it would probably good to a do a bit of tidying... > +/* > + * Convert addr from linear to physical form, valid over the range > + * [addr, addr + *reps * bytes_per_rep]. *reps is adjusted according to > + * the valid computed range. It is always >0 when X86EMUL_OKAY is returned. > + * @pfec indicates the access checks to be performed during page-table walks. > + */ > +static int hvmemul_linear_to_phys( > + unsigned long addr, > + paddr_t *paddr, > + unsigned int bytes_per_rep, > + unsigned long *reps, > + uint32_t pfec, > + struct hvm_emulate_ctxt *hvmemul_ctxt) This can all be re-flowed since arg-per-line is not really canonical style. > +{ > + struct vcpu *curr = current; > + unsigned long pfn, npfn, done, todo, i, offset = addr & ~PAGE_MASK; > + int reverse; Looks like this should be bool. > + > + /* > + * Clip repetitions to a sensible maximum. This avoids extensive looping in > + * this function while still amortising the cost of I/O trap-and-emulate. > + */ > + *reps = min_t(unsigned long, *reps, 4096); > + > + /* With no paging it's easy: linear == physical. */ > + if ( !(curr->arch.hvm.guest_cr[0] & X86_CR0_PG) ) > + { > + *paddr = addr; > + return X86EMUL_OKAY; > + } > + > + /* Reverse mode if this is a backwards multi-iteration string operation. */ > + reverse = (hvmemul_ctxt->ctxt.regs->eflags & X86_EFLAGS_DF) && (*reps > 1); > + > + if ( reverse && ((PAGE_SIZE - offset) < bytes_per_rep) ) > + { > + /* Do page-straddling first iteration forwards via recursion. */ > + paddr_t _paddr; > + unsigned long one_rep = 1; > + int rc = hvmemul_linear_to_phys( > + addr, &_paddr, bytes_per_rep, &one_rep, pfec, hvmemul_ctxt); Blank line here. > + if ( rc != X86EMUL_OKAY ) > + return rc; > + pfn = _paddr >> PAGE_SHIFT; paddr_to_pfn() > + } > + else if ( (pfn = paging_gva_to_gfn(curr, addr, &pfec)) == gfn_x(INVALID_GFN) ) > + { > + if ( pfec & (PFEC_page_paged | PFEC_page_shared) ) > + return X86EMUL_RETRY; > + *reps = 0; > + x86_emul_pagefault(pfec, addr, &hvmemul_ctxt->ctxt); > + return X86EMUL_EXCEPTION; > + } > + > + done = reverse ? bytes_per_rep + offset : PAGE_SIZE - offset; > + todo = *reps * bytes_per_rep; > + for ( i = 1; done < todo; i++ ) > + { > + /* Get the next PFN in the range. */ > + addr += reverse ? -PAGE_SIZE : PAGE_SIZE; > + npfn = paging_gva_to_gfn(curr, addr, &pfec); > + > + /* Is it contiguous with the preceding PFNs? If not then we're done. */ > + if ( (npfn == gfn_x(INVALID_GFN)) || > + (npfn != (pfn + (reverse ? -i : i))) ) > + { > + if ( pfec & (PFEC_page_paged | PFEC_page_shared) ) > + return X86EMUL_RETRY; > + done /= bytes_per_rep; > + if ( done == 0 ) > + { > + ASSERT(!reverse); > + if ( npfn != gfn_x(INVALID_GFN) ) > + return X86EMUL_UNHANDLEABLE; > + *reps = 0; > + x86_emul_pagefault(pfec, addr & PAGE_MASK, &hvmemul_ctxt->ctxt); > + return X86EMUL_EXCEPTION; > + } > + *reps = done; > + break; > + } > + > + done += PAGE_SIZE; > + } > + > + *paddr = ((paddr_t)pfn << PAGE_SHIFT) | offset; pfn_to_paddr() and a blank line before the return. > + return X86EMUL_OKAY; > +} > + Thanks, Paul _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-05-22 13:13 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-20 12:55 [PATCH v4 1/2] x86/emulate: Move hvmemul_linear_to_phys Alexandru Stefan ISAILA 2019-05-20 12:55 ` [Xen-devel] " Alexandru Stefan ISAILA 2019-05-20 12:55 ` [PATCH v4 2/2] x86/emulate: Send vm_event from emulate Alexandru Stefan ISAILA 2019-05-20 12:55 ` [Xen-devel] " Alexandru Stefan ISAILA 2019-05-22 9:56 ` Jan Beulich 2019-05-22 9:56 ` [Xen-devel] " Jan Beulich 2019-05-22 12:59 ` Alexandru Stefan ISAILA 2019-05-22 12:59 ` [Xen-devel] " Alexandru Stefan ISAILA 2019-05-22 13:34 ` Jan Beulich 2019-05-22 13:34 ` [Xen-devel] " Jan Beulich 2019-05-22 13:50 ` Alexandru Stefan ISAILA 2019-05-22 13:50 ` [Xen-devel] " Alexandru Stefan ISAILA 2019-05-22 13:57 ` Jan Beulich 2019-05-22 13:57 ` [Xen-devel] " Jan Beulich 2019-05-30 8:59 ` Alexandru Stefan ISAILA 2019-05-30 8:59 ` [Xen-devel] " Alexandru Stefan ISAILA 2019-05-31 9:16 ` Jan Beulich 2019-05-31 9:16 ` [Xen-devel] " Jan Beulich 2019-05-22 13:13 ` Paul Durrant [this message] 2019-05-22 13:13 ` [Xen-devel] [PATCH v4 1/2] x86/emulate: Move hvmemul_linear_to_phys Paul Durrant 2019-05-22 13:55 ` George Dunlap 2019-05-22 13:55 ` [Xen-devel] " George Dunlap
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