Commit 51644ab7 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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: default avatarRichard Henderson <rth@twiddle.net>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c353e4cc

dma-helpers.c

+5 −0
Original line number Diff line number Diff line
@@ -298,6 +298,11 @@ bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t addr, dma_addr_t len, 
            plen = len;

        }



        if (!address_space_access_valid(dma->as, paddr, len,

                                        dir == DMA_DIRECTION_FROM_DEVICE)) {

            return false;

        }



        len -= plen;

        addr += plen;

    }

exec.c

+21 −0
Original line number Diff line number Diff line
@@ -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.

 * 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.

include/exec/memory.h

+15 −0
Original line number Diff line number Diff line
@@ -866,6 +866,21 @@ MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr, 
                                             hwaddr *xlat, hwaddr *len,

                                             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

 *

 * May map a subset of the requested range, given by and returned in @plen.

include/sysemu/dma.h

+2 −1
Original line number Diff line number Diff line
@@ -113,7 +113,8 @@ static inline bool dma_memory_valid(DMAContext *dma, 
                                    DMADirection dir)

{

    if (!dma_has_iommu(dma)) {

        return true;

        return address_space_access_valid(dma->as, addr, len,

                                          dir == DMA_DIRECTION_FROM_DEVICE);

    } else {

        return iommu_dma_memory_valid(dma, addr, len, dir);

    }