From b680c5ba54946ab205cdb5083bc0a17e3f2fb468 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Fri, 13 Mar 2015 22:23:37 +0100 Subject: [PATCH] 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 Signed-off-by: Greg Kurz Message-Id: <20150313212337.31142.3991.stgit@bahia.local> Signed-off-by: Paolo Bonzini --- kvm-all.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 55025cc366..335438adb5 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -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, -- 2.39.2