Commit b680c5ba authored by Greg Kurz's avatar Greg Kurz Committed by Paolo Bonzini
Browse files

kvm: fix ioeventfd endianness on bi-endian architectures 



KVM expects host endian values. Hosts that don't use the default endianness
need to negate the swap performed in adjust_endianness().

Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
Message-Id: <20150313212337.31142.3991.stgit@bahia.local>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 2034e324

kvm-all.c

+22 −2
Original line number Diff line number Diff line
@@ -528,13 +528,33 @@ int kvm_vm_check_extension(KVMState *s, unsigned int extension) 
    return ret;

}



static uint32_t adjust_ioeventfd_endianness(uint32_t val, uint32_t size)

{

#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)

    /* The kernel expects ioeventfd values in HOST_WORDS_BIGENDIAN

     * endianness, but the memory core hands them in target endianness.

     * For example, PPC is always treated as big-endian even if running

     * on KVM and on PPC64LE.  Correct here.

     */

    switch (size) {

    case 2:

        val = bswap16(val);

        break;

    case 4:

        val = bswap32(val);

        break;

    }

#endif

    return val;

}



static int kvm_set_ioeventfd_mmio(int fd, hwaddr addr, uint32_t val,

                                  bool assign, uint32_t size, bool datamatch)

{

    int ret;

    struct kvm_ioeventfd iofd;



    iofd.datamatch = datamatch ? val : 0;

    iofd.datamatch = datamatch ? adjust_ioeventfd_endianness(val, size) : 0;

    iofd.addr = addr;

    iofd.len = size;

    iofd.flags = 0;
@@ -564,7 +584,7 @@ static int kvm_set_ioeventfd_pio(int fd, uint16_t addr, uint16_t val, 
                                 bool assign, uint32_t size, bool datamatch)

{

    struct kvm_ioeventfd kick = {

        .datamatch = datamatch ? val : 0,

        .datamatch = datamatch ? adjust_ioeventfd_endianness(val, size) : 0,

        .addr = addr,

        .flags = KVM_IOEVENTFD_FLAG_PIO,

        .len = size,