On 01/16/2012 10:59 AM, Stefan Hajnoczi wrote:
On Fri, Jan 13, 2012 at 6:32 PM, Anthony Liguori<aligu...@us.ibm.com> wrote:+ if (strcmp(words[0], "outb") == 0 || + strcmp(words[0], "outw") == 0 || + strcmp(words[0], "outl") == 0) { + uint16_t addr; + uint32_t value; + + g_assert(words[1]&& words[2]); + addr = strtol(words[1], NULL, 0); + value = strtol(words[2], NULL, 0); + + if (words[0][3] == 'b') { + cpu_outb(addr, value); + } else if (words[0][3] == 'w') { + cpu_outw(addr, value); + } else if (words[0][3] == 'l') { + cpu_outl(addr, value); + } + qtest_send_prefix(chr); + qtest_send(chr, "OK\n"); + } else if (strcmp(words[0], "inb") == 0 || + strcmp(words[0], "inw") == 0 || + strcmp(words[0], "inl") == 0) { + uint16_t addr; + uint32_t value = -1U; + + g_assert(words[1]); + addr = strtol(words[1], NULL, 0); + + if (words[0][2] == 'b') { + value = cpu_inb(addr); + } else if (words[0][2] == 'w') { + value = cpu_inw(addr); + } else if (words[0][2] == 'l') { + value = cpu_inl(addr); + } + qtest_send_prefix(chr); + qtest_send(chr, "OK 0x%04x\n", value);Endianness is a little weird here. memory.c will byteswap if target and device endianness differ. Imagine the case where we're on an x86 host, running a ppc guest, reading from PCI configuration space (little-endian).
These functions expect to get host native endian. The qtest wire protocol is a string (which has no endianness) and converts it to host native endian.
Since ppc (target endian) is big-endian and the device is little-endian the value read/written will be byteswapped. However, our qtest runs on the host and therefore we don't want that automatic swap (or we need to neutralize it by performing another byteswap on top).
ppc wouldn't use outb/inb. It would do mmio to the PIO region which would send it through the host controller (which would do byte swapping as necessary).
So a qtest test case would have to do little endian MMIO to interact with the PCI bus.
Regards, Anthony Liguori
Stefan
