first patch fixes crash in 9p code that occasionally happens also in nixos tests
second patch fixes io errors from discards in aio io engine with virtio-scsi
Tested building qemu_kvm, qemu_full, and qemu_test on x86_64-linux.
Also tested booting a VM generated with nixos-rebuild build-vm.
I wasn't able to test building pkgsMusl.qemu_kvm, because of many
build failures in dependencies.
5e25995295 ("qemu: 2.6.1 -> 2.7.0") added this, because the QEMU
build failed without it. That's no longer the case, so we can bring
back stack protection.
It fails on darwin due to missing `patchelf` and the missing ELFs:
```
/nix/store/...-auto-patchelf-hook/nix-support/setup-hook: line 220: -l: command not found
```
In libc++ starting with LLVM8 there's `<version>` include in `cstddef`:
The following things also align:
* QEMU has a file called `VERSION` in repo root
* QEMU prepends repo root to include path in build
* macOS has a case-insensetive filesystem
All of this combined means that `VERSION` file is included as a header.
Working around this be renaming `VERSION` -> `QEMU_VERSION` to resolve ambiguity.
The problem really only appears on `aarch64-darwin`, since on `x86_64-darwin`
there are no C++ files to compile. The workaround is harmless enough to apply.
This change produces the following warning:
```
... configure: line 619: sysctl: command not found
```
It's benign and sysctl is only useful on MacOS X Leopard:
* https://github.com/qemu/qemu/blob/v5.2.0/configure#L615-L621
Leopard is 13 years old and is not supported by Nix.
The sysctl check is removed in qemu master branch already.
Plus aarch64-darwin is coming in #105026, so there's no reason to force x86_64.
The qemu-user variants as used by binfmt emulation through
`(lib.systems.elaborate lib.systems.examples.aarch64-multiplatform).emulator pkgs`
does not install a .desktop file since qemu 5.2.0. This change allows
the build to continue if deletion of the desktop file fails.
Updates to latest version of QEMU.
The build system has changed to ninja.
There are several configuration flags that aren't enabled. I will
defer to maintainers on those.
Adds autoPatchelfHook for patching output dynamically linked binaries.
qemu: use Nix's meson vs bundled
qemu: remove custom directory locations
It appears that these directories are no longer automatically prefixed
with $out/, so they are now trying to write to the system /etc/, /var/
directories, which is not permitted in sandbox.
The default directories seem to work OK, so using those.
While receiving packets via e1000e_write_packet_to_guest an infinite
loop could be triggered if the receive descriptor had a NULL buffer
address.
A privileged guest user could use this to induce a DoS Scenario.
Fixes: CVE-2020-28916
An assert(3) failure issue was found in the networking helper functions of QEMU. It could occur in the eth_get_gso_type() routine, if a packet does not have a valid networking L3 protocol (ex. IPv4, IPv6) value. A guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.
Fixes: CVE-2020-27617
