On Tue, Dec 10, 2019 at 1:04 AM Alistair Francis <alistair23@gmail.com> wrote:
>
> On Mon, Dec 9, 2019 at 2:55 PM Aleksandar Markovic
> <aleksandar.m.mail@gmail.com> wrote:
> >
> >
> >
> > On Monday, December 9, 2019, Alistair Francis <alistair.francis@wdc.com> wrote:
> >>
> >> This patch series adds the RISC-V Hypervisor extension v0.5. This is the
> >> latest draft spec of the Hypervisor extension.
> >>
> >
> > Hi, Alistair,
> >
> > I have a question for you:
> >
> > Let's say this series is accepted. And let's say, next year, the draft spec of RISC-V Hypervisor extension v0.6 is released, and you or somebody else comes up with series on QEMU support for it, and that series is accepted too. What would happen afterwards:
> >
> > A. Both support for v0.5 and v0.6 would continue to coexist perpetually
> >
> > B. Support for v0.5 would be deprecated according to QEMU deprecation rules, and in two cycle would disappear
> >
> > C. Support for v0.5 would abruptly stop existing
>
> My current plan is to upgrade the implementation to the next version
> and drop v0.5 when a new spec release. happens.
>
> The justification for this is that the Hypervisor is a draft
> extension, disabled by default and marked as experimental. Therefore I
> think it's ok to just support the latest version of the spec.
>
OK. Thanks for clarification.
> Alistair
>
> >
> > D. Something else
> >
> > ?
> >
> > Thanks,
> > Aleksandar
> >
> >
> >>
> >> The Hypervisor extension is disabled by default, so this series should
> >> result in no changes to anyone using QEMU unless they enable the
> >> extension. The extention can be enabled with the -cpu property (see
> >> below).
> >>
> >> Testing of this implementation has been done by using the baremetal
> >> Xvisor Hypervisor. We are able to run two Linux guests (that's all I
> >> have tried) as guests in 64-bit. In 32-bit so far I can only run
> >> baremetal guests, but I think this is a baremetal boot loader issue and
> >> not an issue in QEMU.
> >>
> >> The RISC-V KVM implementation was also written using these patches. The
> >> KVM implementation is currently under review.
> >>
> >> At the moment this spec is in a draft state and is subject to change. As
> >> QEMU is extreamly useful in early bring up I think it makes sense for
> >> QEMU to support non-frozen extensions.
> >>
> >> Thanks to Anup for doing the initial port of Xvisor. The port is avaliable here:
> >> https://github.com/avpatel/xvisor-next and will run on QEMU.
> >>
> >> Also thanks to Atish for implementing the SBI call support in Xvisor and
> >> for lots of help debugging.
> >>
> >> To run this yourself:
> >> 1. Apply this patch series to QEMU. The latest branch can be found here:
> >> https://github.com/alistair23/qemu/tree/mainline/alistair/riscv-hyp-ext-v0.5.next
> >> 2. Get the version of OpenSBI that supports the H extension. This can
> >> be found here:
> >> https://github.com/avpatel/opensbi/tree/riscv_hyp_ext_0_5_v1
> >> 3. Build the next release of Xvisor. It is available here:
> >> https://github.com/avpatel/xvisor-next
> >> 4. Make sure you build the Xvisor tests, see here for details:
> >> https://github.com/avpatel/xvisor-next/tree/master/tests/riscv/virt64/linux
> >> 5. Run QEMU:
> >> ./riscv64-softmmu/qemu-system-riscv64 -nographic \
> >> -machine virt -cpu rv64,x-h=true \
> >> -serial mon:stdio -serial null -m 4G \
> >> -device loader,file=vmm.bin,addr=0x80200000 \
> >> -kernel fw_jump.elf \
> >> -initrd vmm-disk-linux.img \
> >> -append "vmm.console=uart@10000000 vmm.bootcmd=\"vfs mount initrd /;vfs run /boot.xscript;vfs cat /system/banner.txt\""
> >>
> >> Once you get to the prompt you can start the geust by running:
> >> guest kick guest0
> >> You can then bind to the serial port using:
> >> vserial bind guest0/uart0
> >> Then you can start Linux using:
> >> autoexec
> >>
> >> This was all tested with the mainline 5.2/5.3 kernels.
> >>
> >> There is very early work on a Xen port as well which is avaliable here:
> >> https://github.com/alistair23/xen/tree/alistair/riscv-port
> >>
> >> ToDo/Issues
> >> - Get 32-bit fully working
> >>
> >>
> >>
> >> Alistair Francis (36):
> >> target/riscv: Convert MIP CSR to target_ulong
> >> target/riscv: Don't set write permissions on dirty PTEs
> >> target/riscv: Add the Hypervisor extension
> >> target/riscv: Add the Hypervisor CSRs to CPUState
> >> target/riscv: Add support for the new execption numbers
> >> target/riscv: Rename the H irqs to VS irqs
> >> target/riscv: Add the virtulisation mode
> >> target/riscv: Add the force HS exception mode
> >> target/riscv: Fix CSR perm checking for HS mode
> >> target/riscv: Print priv and virt in disas log
> >> target/riscv: Dump Hypervisor registers if enabled
> >> target/riscv: Add Hypervisor CSR access functions
> >> target/riscv: Add Hypervisor virtual CSRs accesses
> >> target/riscv: Add Hypervisor virtual CSRs accesses
> >> target/riscv: Convert mstatus to pointers
> >> target/riscv: Add virtual register swapping function
> >> target/riscv: Set VS bits in mideleg for Hyp extension
> >> target/riscv: Extend the MIE CSR to support virtulisation
> >> target/riscv: Extend the SIP CSR to support virtulisation
> >> target/riscv: Add support for virtual interrupt setting
> >> target/ricsv: Flush the TLB on virtulisation mode changes
> >> target/riscv: Generate illegal instruction on WFI when V=1
> >> target/riscv: Add hypvervisor trap support
> >> target/riscv: Add Hypervisor trap return support
> >> target/riscv: Add hfence instructions
> >> target/riscv: Remove the hret instruction
> >> target/riscv: Disable guest FP support based on virtual status
> >> target/riscv: Mark both sstatus and vsstatus as dirty
> >> target/riscv: Respect MPRV and SPRV for floating point ops
> >> target/riscv: Allow specifying MMU stage
> >> target/riscv: Implement second stage MMU
> >> target/riscv: Raise the new execptions when 2nd stage translation
> >> fails
> >> target/riscv: Set htval and mtval2 on execptions
> >> target/riscv: Add support for the 32-bit MSTATUSH CSR
> >> target/riscv: Add the MSTATUS_MPV_ISSET helper macro
> >> target/riscv: Allow enabling the Hypervisor extension
> >>
> >> target/riscv/cpu.c | 71 ++-
> >> target/riscv/cpu.h | 58 +-
> >> target/riscv/cpu_bits.h | 111 ++--
> >> target/riscv/cpu_helper.c | 501 +++++++++++++++---
> >> target/riscv/csr.c | 389 +++++++++++++-
> >> target/riscv/gdbstub.c | 11 +-
> >> target/riscv/insn32.decode | 22 +-
> >> .../riscv/insn_trans/trans_privileged.inc.c | 45 +-
> >> target/riscv/op_helper.c | 81 ++-
> >> target/riscv/translate.c | 34 ++
> >> 10 files changed, 1161 insertions(+), 162 deletions(-)
> >>
> >> --
> >> 2.24.0
> >>
> >>