ruvm 0.5.6

This patch runs the Arm virt board on KVM, brings in virtio-sound and puts both riscv64 and aarch64 virt under the qtest accelerator.

For M6: the virt board now runs on KVM on Arm Linux hosts (#244) with -accel kvm, -enable-kvm and -machine accel=kvm and QEMU's errors (#248). The VM's IPA space is sized from KVM_CAP_ARM_VM_IPA_SIZE and the memory map follows it (#249, #255). Arm KVM guests get a steal time record per vCPU (#257), and -cpu host gets SVE and pointer authentication when the host has them (#258). None of the Arm KVM work has run on an Arm host with /dev/kvm yet, which #227 tracks. virtio-sound is in on q35 (#246), and in a Linux guest its playback into the wav backend matched QEMU 11.1 byte for byte. riscv64 virt (#251) and aarch64 virt (#256) now run under the qtest accelerator, and riscv64 virt takes the aclint property (#253). -nic none and -net none are accepted (#259), and the firmware and kernel load errors on x86 read as QEMU's do (#250). ruvm builds and passes clippy on macOS and Windows again, and tests that wait on a guest now time out instead of hanging (#254). The root tap test accepts EIO from a tap that is down (#247).

For M7: mremap of part of a merged mapping and failed host moves now behave as on Linux (#245).

What's Changed

• machine-arm: run the virt board on KVM by @tamnd in #244
• linux-user: mremap of part of a merged mapping and failed host moves by @tamnd in #245
• hw-audio: add virtio-sound by @tamnd in #246
• net: accept EIO from a tap that is down in the root test by @tamnd in #247
• system: -accel kvm for the virt board on Arm hosts by @tamnd in #248
• system: lay the virt memory map out for a 40-bit IPA under KVM by @tamnd in #249
• machine-x86: print the firmware and kernel load errors as QEMU does by @tamnd in #250
• system: run riscv64 virt under the qtest accelerator by @tamnd in #251
• machine-riscv: add the aclint property to virt by @tamnd in #253
• net, cli: build on macOS and Windows again and stop tests that hang by @tamnd in #254
• machine-arm: size the Arm KVM VM's IPA space from KVM_CAP_ARM_VM_IPA_SIZE by @tamnd in #255
• system: run aarch64 virt under the qtest accelerator by @tamnd in #256
• machine-arm: give Arm KVM guests a steal time record per vCPU by @tamnd in #257
• machine-arm: SVE and pointer authentication for -cpu host under KVM by @tamnd in #258
• system: accept -nic none and -net none by @tamnd in #259
• Release 0.5.6 by @tamnd in #260

Full Changelog: v0.5.5...v0.5.6