On 12/16/2017 07:49 AM, Peter Maydell wrote: > On 15 December 2017 at 20:37, Wei Huang <w...@redhat.com> wrote: >> This patch adds the migration test support for aarch64. The test code, >> which implements the same functionality as x86, is compiled into a binary >> and booted as a kernel to qemu. Here are the design ideas: >> >> * We choose this -kernel design because aarch64 QEMU doesn't provide a >> built-in fw like x86 does. So instead of relying on a boot loader, we >> use -kernel approach for aarch64. >> * The serial output is sent to PL011 directly. >> * The physical memory base for mach-virt machine is 0x40000000. We have >> to change the start_address and end_address for aarch64. >> * The downtime is changed from 0.001 to 0.1. Without this change, we saw >> migration stalled. This problem is still under analysis and needs to be >> resolved before removing RFC for this patch. >> >> The test code is as the following: >> >> .section .text > > >> #if defined(__linux__) >> @@ -125,6 +125,18 @@ unsigned char bootsect[] = { >> 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x55, 0xaa >> }; >> >> +unsigned char aarch64_kernel[] = { >> + 0x00, 0x10, 0x38, 0xd5, 0x00, 0xf8, 0x7f, 0x92, 0x00, 0x10, 0x18, 0xd5, >> + 0xdf, 0x3f, 0x03, 0xd5, 0x24, 0x08, 0x80, 0x52, 0x05, 0x20, 0xa1, 0xd2, >> + 0xa4, 0x00, 0x00, 0x39, 0x06, 0x00, 0x80, 0x52, 0x03, 0xc8, 0xa8, 0xd2, >> + 0x02, 0x02, 0xa8, 0xd2, 0x41, 0x00, 0x40, 0x39, 0x21, 0x04, 0x00, 0x11, >> + 0x41, 0x00, 0x00, 0x39, 0x42, 0x04, 0x40, 0x91, 0x5f, 0x00, 0x03, 0xeb, >> + 0x6b, 0xff, 0xff, 0x54, 0xc6, 0x04, 0x00, 0x11, 0xc6, 0x1c, 0x00, 0x12, >> + 0xdf, 0x00, 0x00, 0x71, 0xc1, 0xfe, 0xff, 0x54, 0x44, 0x08, 0x80, 0x52, >> + 0x05, 0x20, 0xa1, 0xd2, 0xa4, 0x00, 0x00, 0x39, 0xf2, 0xff, 0xff, 0x97 >> +}; >> +unsigned int aarch64_kernel_len = 96; > > I'm not really a fan of this steadily increasing number of hex-encoded > target binary blobs in the tests directory, but if we must, I > think this would be easier to read as an array of uint32_t, > so that each entry is one instruction word.
This make sense given that ARM has fixed-length instructions. > > (If your claim is that nobody cares about the hex because > they'll just rebuild from the source code in the commit > message, I would suggest that that makes the source code > the 'preferred form for modification' under the GPL...) > Overall I agree with your comments. For this specific migration-test, PPC's approach is my preferred one. But unfortunately, ARM doesn't have a built-in firmware in QEMU to run a scripting test. So either we have to use a per-compiled binary blob, or find a way to build this blob from source inside QEMU. The second one might take a while to complete though. > But I think at some point we really need to stop doing > this and instead figure out a mechanism for building > target code as part of the QEMU build-and-test. > It is coming up increasingly often: > * code to run on the guest in tests > * the bios blobs (at the moment we special case > the x86 bios blobs and assume we can compile them > with the host C compiler, which is not great) > * for linux-user on several architectures we would like > to properly implement a guest VDSO > > thanks > -- PMM >