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From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: xen-devel <xen-devel@lists.xenproject.org>, Keir Fraser <keir@xen.org>
Subject: Re: [PATCH 1/5] x86/HVM: properly handle backward string instruction emulation
Date: Tue, 8 Oct 2013 17:36:48 +0100	[thread overview]
Message-ID: <525434A0.6050500@citrix.com> (raw)
In-Reply-To: <5249915002000078000F8077@nat28.tlf.novell.com>


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On 30/09/13 13:57, Jan Beulich wrote:
> Multiplying a signed 32-bit quantity with an unsigned 32-bit quantity
> produces an unsigned 32-bit result, yet for emulation of backward
> string instructions we need the result sign extended before getting
> added to the base address.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

>
> --- a/xen/arch/x86/hvm/intercept.c
> +++ b/xen/arch/x86/hvm/intercept.c
> @@ -48,7 +48,7 @@ static int hvm_mmio_access(struct vcpu *
>                             hvm_mmio_write_t write_handler)
>  {
>      unsigned long data;
> -    int rc = X86EMUL_OKAY, i, sign = p->df ? -1 : 1;
> +    int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
>  
>      if ( !p->data_is_ptr )
>      {
> @@ -68,13 +68,10 @@ static int hvm_mmio_access(struct vcpu *
>          {
>              int ret;
>  
> -            rc = read_handler(v, p->addr + (sign * i * p->size), p->size,
> -                              &data);
> +            rc = read_handler(v, p->addr + step * i, p->size, &data);
>              if ( rc != X86EMUL_OKAY )
>                  break;
> -            ret = hvm_copy_to_guest_phys(p->data + (sign * i * p->size),
> -                                         &data,
> -                                         p->size);
> +            ret = hvm_copy_to_guest_phys(p->data + step * i, &data, p->size);
>              if ( (ret == HVMCOPY_gfn_paged_out) || 
>                   (ret == HVMCOPY_gfn_shared) )
>              {
> @@ -87,8 +84,7 @@ static int hvm_mmio_access(struct vcpu *
>      {
>          for ( i = 0; i < p->count; i++ )
>          {
> -            switch ( hvm_copy_from_guest_phys(&data,
> -                                              p->data + sign * i * p->size,
> +            switch ( hvm_copy_from_guest_phys(&data, p->data + step * i,
>                                                p->size) )
>              {
>              case HVMCOPY_okay:
> @@ -109,8 +105,7 @@ static int hvm_mmio_access(struct vcpu *
>              }
>              if ( rc != X86EMUL_OKAY )
>                  break;
> -            rc = write_handler(v, p->addr + (sign * i * p->size), p->size,
> -                               data);
> +            rc = write_handler(v, p->addr + step * i, p->size, data);
>              if ( rc != X86EMUL_OKAY )
>                  break;
>          }
> @@ -142,7 +137,7 @@ int hvm_mmio_intercept(ioreq_t *p)
>  
>  static int process_portio_intercept(portio_action_t action, ioreq_t *p)
>  {
> -    int rc = X86EMUL_OKAY, i, sign = p->df ? -1 : 1;
> +    int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
>      uint32_t data;
>  
>      if ( !p->data_is_ptr )
> @@ -167,8 +162,7 @@ static int process_portio_intercept(port
>              rc = action(IOREQ_READ, p->addr, p->size, &data);
>              if ( rc != X86EMUL_OKAY )
>                  break;
> -            (void)hvm_copy_to_guest_phys(p->data + sign*i*p->size,
> -                                         &data, p->size);
> +            (void)hvm_copy_to_guest_phys(p->data + step * i, &data, p->size);
>          }
>      }
>      else /* p->dir == IOREQ_WRITE */
> @@ -176,8 +170,7 @@ static int process_portio_intercept(port
>          for ( i = 0; i < p->count; i++ )
>          {
>              data = 0;
> -            switch ( hvm_copy_from_guest_phys(&data,
> -                                              p->data + sign * i * p->size,
> +            switch ( hvm_copy_from_guest_phys(&data, p->data + step * i,
>                                                p->size) )
>              {
>              case HVMCOPY_okay:
> --- a/xen/arch/x86/hvm/io.c
> +++ b/xen/arch/x86/hvm/io.c
> @@ -294,7 +294,7 @@ void hvm_io_assist(void)
>  
>  static int dpci_ioport_read(uint32_t mport, ioreq_t *p)
>  {
> -    int i, sign = p->df ? -1 : 1;
> +    int i, step = p->df ? -p->size : p->size;
>      uint32_t data = 0;
>  
>      for ( i = 0; i < p->count; i++ )
> @@ -317,8 +317,7 @@ static int dpci_ioport_read(uint32_t mpo
>          if ( p->data_is_ptr )
>          {
>              int ret;
> -            ret = hvm_copy_to_guest_phys(p->data + (sign * i * p->size), &data,
> -                                         p->size);
> +            ret = hvm_copy_to_guest_phys(p->data + step * i, &data, p->size);
>              if ( (ret == HVMCOPY_gfn_paged_out) ||
>                   (ret == HVMCOPY_gfn_shared) )
>                  return X86EMUL_RETRY;
> @@ -332,7 +331,7 @@ static int dpci_ioport_read(uint32_t mpo
>  
>  static int dpci_ioport_write(uint32_t mport, ioreq_t *p)
>  {
> -    int i, sign = p->df ? -1 : 1;
> +    int i, step = p->df ? -p->size : p->size;
>      uint32_t data;
>  
>      for ( i = 0; i < p->count; i++ )
> @@ -340,8 +339,7 @@ static int dpci_ioport_write(uint32_t mp
>          data = p->data;
>          if ( p->data_is_ptr )
>          {
> -            switch ( hvm_copy_from_guest_phys(&data,
> -                                              p->data + sign * i * p->size,
> +            switch ( hvm_copy_from_guest_phys(&data, p->data + step * i,
>                                                p->size) )
>              {
>              case HVMCOPY_okay:
> --- a/xen/arch/x86/hvm/stdvga.c
> +++ b/xen/arch/x86/hvm/stdvga.c
> @@ -467,15 +467,17 @@ static uint32_t read_data;
>  static int mmio_move(struct hvm_hw_stdvga *s, ioreq_t *p)
>  {
>      int i;
> -    int sign = p->df ? -1 : 1;
> +    uint64_t addr = p->addr;
>      p2m_type_t p2mt;
>      struct domain *d = current->domain;
>  
>      if ( p->data_is_ptr )
>      {
> +        uint64_t data = p->data, tmp;
> +        int step = p->df ? -p->size : p->size;
> +
>          if ( p->dir == IOREQ_READ )
>          {
> -            uint64_t addr = p->addr, data = p->data, tmp;
>              for ( i = 0; i < p->count; i++ ) 
>              {
>                  tmp = stdvga_mem_read(addr, p->size);
> @@ -498,13 +500,12 @@ static int mmio_move(struct hvm_hw_stdvg
>                      ASSERT(!dp);
>                      stdvga_mem_write(data, tmp, p->size);
>                  }
> -                data += sign * p->size;
> -                addr += sign * p->size;
> +                data += step;
> +                addr += step;
>              }
>          }
>          else
>          {
> -            uint32_t addr = p->addr, data = p->data, tmp;
>              for ( i = 0; i < p->count; i++ )
>              {
>                  if ( hvm_copy_from_guest_phys(&tmp, data, p->size) !=
> @@ -523,31 +524,18 @@ static int mmio_move(struct hvm_hw_stdvg
>                      tmp = stdvga_mem_read(data, p->size);
>                  }
>                  stdvga_mem_write(addr, tmp, p->size);
> -                data += sign * p->size;
> -                addr += sign * p->size;
> +                data += step;
> +                addr += step;
>              }
>          }
>      }
>      else
>      {
> +        ASSERT(p->count == 1);
>          if ( p->dir == IOREQ_READ )
> -        {
> -            uint32_t addr = p->addr;
> -            for ( i = 0; i < p->count; i++ )
> -            {
> -                p->data = stdvga_mem_read(addr, p->size);
> -                addr += sign * p->size;
> -            }
> -        }
> +            p->data = stdvga_mem_read(addr, p->size);
>          else
> -        {
> -            uint32_t addr = p->addr;
> -            for ( i = 0; i < p->count; i++ )
> -            {
> -                stdvga_mem_write(addr, p->data, p->size);
> -                addr += sign * p->size;
> -            }
> -        }
> +            stdvga_mem_write(addr, p->data, p->size);
>      }
>  
>      read_data = p->data;
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel


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  reply	other threads:[~2013-10-08 16:36 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-30 12:51 [PATCH 0/5] x86/HVM: XSA-63 follow-ups Jan Beulich
2013-09-30 12:57 ` [PATCH 1/5] x86/HVM: properly handle backward string instruction emulation Jan Beulich
2013-10-08 16:36   ` Andrew Cooper [this message]
2013-09-30 12:57 ` [PATCH 2/5] x86/HVM: fix direct PCI port I/O emulation retry and error handling Jan Beulich
2013-10-08 18:13   ` Andrew Cooper
2013-09-30 12:58 ` [PATCH 3/5] x86/HVM: don't ignore hvm_copy_to_guest_phys() errors during I/O intercept Jan Beulich
2013-10-08 18:20   ` Andrew Cooper
2013-10-09  7:48     ` Jan Beulich
2013-09-30 12:58 ` [PATCH 4/5] x86/HVM: properly deal with hvm_copy_*_guest_phys() errors Jan Beulich
2013-09-30 13:07   ` Andrew Cooper
2013-09-30 12:59 ` [PATCH 5/5] x86/HVM: cache emulated instruction for retry processing Jan Beulich
2013-10-10 11:35   ` Andrew Cooper
2013-12-18  8:36   ` Zhang, Yang Z
2013-12-18  8:48     ` Jan Beulich
2013-12-18  9:40       ` Zhang, Yang Z
2013-12-18 10:53         ` Jan Beulich
2013-12-24 11:29           ` Zhang, Yang Z
2014-01-07  8:28             ` Jan Beulich
2014-01-07  8:54               ` Zhang, Yang Z
2014-01-07  9:43                 ` Egger, Christoph
2014-01-08  5:50                   ` Zhang, Yang Z
2014-01-09 12:19                     ` Egger, Christoph
2014-01-16  4:42                       ` Zhang, Yang Z
2014-01-16  8:23                         ` Jan Beulich
2014-01-17  2:53                           ` Zhang, Yang Z
2013-10-08 15:10 ` Ping: [PATCH 0/5] x86/HVM: XSA-63 follow-ups Jan Beulich
2013-10-14  7:29 ` Keir Fraser

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