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: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Message-Id: <20150313212337.31142.3991.stgit@bahia.local>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Greg Kurz 2015-03-13 22:23:37 +01:00 committed by Paolo Bonzini
parent 2034e324da
commit b680c5ba54

View file

@ -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,