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[PATCH v5 1/3] memory: drop guest writes to read-only ram device regions

Yan Zhao posted 3 patches 5 years, 6 months ago
There is a newer version of this series
[PATCH v5 1/3] memory: drop guest writes to read-only ram device regions
Posted by Yan Zhao 5 years, 6 months ago 
for ram device regions, drop guest writes if the regions is read-only.

Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Xin Zeng <xin.zeng@intel.com>
---
 memory.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/memory.c b/memory.c
index 601b749906..90a748912f 100644
--- a/memory.c
+++ b/memory.c
@@ -34,6 +34,7 @@
 #include "sysemu/accel.h"
 #include "hw/boards.h"
 #include "migration/vmstate.h"
+#include "qemu/log.h"
 
 //#define DEBUG_UNASSIGNED
 
@@ -1307,12 +1308,19 @@ static uint64_t memory_region_ram_device_read(void *opaque,
     return data;
 }
 
-static void memory_region_ram_device_write(void *opaque, hwaddr addr,
-                                           uint64_t data, unsigned size)
+static MemTxResult memory_region_ram_device_write(void *opaque, hwaddr addr,
+                                           uint64_t data, unsigned size,
+                                           MemTxAttrs attrs)
 {
     MemoryRegion *mr = opaque;
 
     trace_memory_region_ram_device_write(get_cpu_index(), mr, addr, data, size);
+    if (mr->readonly) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "Invalid write to read only ram device region addr 0x%"
+                       HWADDR_PRIx" size %u\n", addr, size);
+        return MEMTX_ERROR;
+    }
 
     switch (size) {
     case 1:
@@ -1328,11 +1336,12 @@ static void memory_region_ram_device_write(void *opaque, hwaddr addr,
         *(uint64_t *)(mr->ram_block->host + addr) = data;
         break;
     }
+    return MEMTX_OK;
 }
 
 static const MemoryRegionOps ram_device_mem_ops = {
     .read = memory_region_ram_device_read,
-    .write = memory_region_ram_device_write,
+    .write_with_attrs = memory_region_ram_device_write,
     .endianness = DEVICE_HOST_ENDIAN,
     .valid = {
         .min_access_size = 1,
-- 
2.17.1
Re: [PATCH v5 1/3] memory: drop guest writes to read-only ram device regions
Posted by Philippe Mathieu-Daudé 5 years, 6 months ago 
On 4/30/20 7:19 AM, Yan Zhao wrote:
> for ram device regions, drop guest writes if the regions is read-only.
> 
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
> Signed-off-by: Xin Zeng <xin.zeng@intel.com>
> ---
>   memory.c | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/memory.c b/memory.c
> index 601b749906..90a748912f 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -34,6 +34,7 @@
>   #include "sysemu/accel.h"
>   #include "hw/boards.h"
>   #include "migration/vmstate.h"
> +#include "qemu/log.h"
>   
>   //#define DEBUG_UNASSIGNED
>   
> @@ -1307,12 +1308,19 @@ static uint64_t memory_region_ram_device_read(void *opaque,
>       return data;
>   }
>   
> -static void memory_region_ram_device_write(void *opaque, hwaddr addr,
> -                                           uint64_t data, unsigned size)
> +static MemTxResult memory_region_ram_device_write(void *opaque, hwaddr addr,
> +                                           uint64_t data, unsigned size,
> +                                           MemTxAttrs attrs)

Style alignment is now of and can be adjusted easily.

>   {
>       MemoryRegion *mr = opaque;
>   
>       trace_memory_region_ram_device_write(get_cpu_index(), mr, addr, data, size);
> +    if (mr->readonly) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "Invalid write to read only ram device region addr 0x%"
> +                       HWADDR_PRIx" size %u\n", addr, size);

Style alignment of here too.

Otherwise:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +        return MEMTX_ERROR;
> +    }
>   
>       switch (size) {
>       case 1:
> @@ -1328,11 +1336,12 @@ static void memory_region_ram_device_write(void *opaque, hwaddr addr,
>           *(uint64_t *)(mr->ram_block->host + addr) = data;
>           break;
>       }
> +    return MEMTX_OK;
>   }
>   
>   static const MemoryRegionOps ram_device_mem_ops = {
>       .read = memory_region_ram_device_read,
> -    .write = memory_region_ram_device_write,
> +    .write_with_attrs = memory_region_ram_device_write,
>       .endianness = DEVICE_HOST_ENDIAN,
>       .valid = {
>           .min_access_size = 1,
>
Re: [PATCH v5 1/3] memory: drop guest writes to read-only ram device regions
Posted by Yan Zhao 5 years, 6 months ago 
On Thu, Apr 30, 2020 at 03:07:21PM +0800, Philippe Mathieu-Daudé wrote:
> On 4/30/20 7:19 AM, Yan Zhao wrote:
> > for ram device regions, drop guest writes if the regions is read-only.
> > 
> > Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
> > Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
> > Signed-off-by: Xin Zeng <xin.zeng@intel.com>
> > ---
> >   memory.c | 15 ++++++++++++---
> >   1 file changed, 12 insertions(+), 3 deletions(-)
> > 
> > diff --git a/memory.c b/memory.c
> > index 601b749906..90a748912f 100644
> > --- a/memory.c
> > +++ b/memory.c
> > @@ -34,6 +34,7 @@
> >   #include "sysemu/accel.h"
> >   #include "hw/boards.h"
> >   #include "migration/vmstate.h"
> > +#include "qemu/log.h"
> >   
> >   //#define DEBUG_UNASSIGNED
> >   
> > @@ -1307,12 +1308,19 @@ static uint64_t memory_region_ram_device_read(void *opaque,
> >       return data;
> >   }
> >   
> > -static void memory_region_ram_device_write(void *opaque, hwaddr addr,
> > -                                           uint64_t data, unsigned size)
> > +static MemTxResult memory_region_ram_device_write(void *opaque, hwaddr addr,
> > +                                           uint64_t data, unsigned size,
> > +                                           MemTxAttrs attrs)
> 
> Style alignment is now of and can be adjusted easily.
> 
> >   {
> >       MemoryRegion *mr = opaque;
> >   
> >       trace_memory_region_ram_device_write(get_cpu_index(), mr, addr, data, size);
> > +    if (mr->readonly) {
> > +        qemu_log_mask(LOG_GUEST_ERROR,
> > +                      "Invalid write to read only ram device region addr 0x%"
> > +                       HWADDR_PRIx" size %u\n", addr, size);
> 
> Style alignment of here too.
> 
> Otherwise:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Thanks! I'll update it right now!

> 
> > +        return MEMTX_ERROR;
> > +    }
> >   
> >       switch (size) {
> >       case 1:
> > @@ -1328,11 +1336,12 @@ static void memory_region_ram_device_write(void *opaque, hwaddr addr,
> >           *(uint64_t *)(mr->ram_block->host + addr) = data;
> >           break;
> >       }
> > +    return MEMTX_OK;
> >   }
> >   
> >   static const MemoryRegionOps ram_device_mem_ops = {
> >       .read = memory_region_ram_device_read,
> > -    .write = memory_region_ram_device_write,
> > +    .write_with_attrs = memory_region_ram_device_write,
> >       .endianness = DEVICE_HOST_ENDIAN,
> >       .valid = {
> >           .min_access_size = 1,
> > 
>

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