memory: add address_space_access_valid

The old-style IOMMU lets you check whether an access is valid in a
given DMAContext.  There is no equivalent for AddressSpace in the
memory API, implement it with a lookup of the dispatch tree.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2013-04-11 15:40:59 +02:00
parent c353e4cc08
commit 51644ab70b
4 changed files with 43 additions and 1 deletions

View File

@ -298,6 +298,11 @@ bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t addr, dma_addr_t len,
plen = len; plen = len;
} }
if (!address_space_access_valid(dma->as, paddr, len,
dir == DMA_DIRECTION_FROM_DEVICE)) {
return false;
}
len -= plen; len -= plen;
addr += plen; addr += plen;
} }

21
exec.c
View File

@ -2067,6 +2067,27 @@ static void cpu_notify_map_clients(void)
} }
} }
bool address_space_access_valid(AddressSpace *as, hwaddr addr, int len, bool is_write)
{
MemoryRegionSection *section;
hwaddr l, xlat;
while (len > 0) {
l = len;
section = address_space_translate(as, addr, &xlat, &l, is_write);
if (!memory_access_is_direct(section->mr, is_write)) {
l = memory_access_size(l, addr);
if (!memory_region_access_valid(section->mr, xlat, l, is_write)) {
return false;
}
}
len -= l;
addr += l;
}
return true;
}
/* Map a physical memory region into a host virtual address. /* Map a physical memory region into a host virtual address.
* May map a subset of the requested range, given by and returned in *plen. * May map a subset of the requested range, given by and returned in *plen.
* May return NULL if resources needed to perform the mapping are exhausted. * May return NULL if resources needed to perform the mapping are exhausted.

View File

@ -866,6 +866,21 @@ MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr,
hwaddr *xlat, hwaddr *len, hwaddr *xlat, hwaddr *len,
bool is_write); bool is_write);
/* address_space_access_valid: check for validity of accessing an address
* space range
*
* Check whether memory is assigned to the given address space range.
*
* For now, addr and len should be aligned to a page size. This limitation
* will be lifted in the future.
*
* @as: #AddressSpace to be accessed
* @addr: address within that address space
* @len: length of the area to be checked
* @is_write: indicates the transfer direction
*/
bool address_space_access_valid(AddressSpace *as, hwaddr addr, int len, bool is_write);
/* address_space_map: map a physical memory region into a host virtual address /* address_space_map: map a physical memory region into a host virtual address
* *
* May map a subset of the requested range, given by and returned in @plen. * May map a subset of the requested range, given by and returned in @plen.

View File

@ -113,7 +113,8 @@ static inline bool dma_memory_valid(DMAContext *dma,
DMADirection dir) DMADirection dir)
{ {
if (!dma_has_iommu(dma)) { if (!dma_has_iommu(dma)) {
return true; return address_space_access_valid(dma->as, addr, len,
dir == DMA_DIRECTION_FROM_DEVICE);
} else { } else {
return iommu_dma_memory_valid(dma, addr, len, dir); return iommu_dma_memory_valid(dma, addr, len, dir);
} }