[v7,0/3] hw/riscv/virt: pflash improvements

Message

Sunil V L June 1, 2023, 4:59 a.m. UTC

This series improves the pflash usage in RISC-V virt machine with solutions to
below issues.

1) Currently the first pflash is reserved for ROM/M-mode firmware code. But S-mode
payload firmware like EDK2 need both pflash devices to have separate code and variable
store so that OS distros can keep the FW code as read-only. 

The issue is reported at
https://salsa.debian.org/qemu-team/edk2/-/commit/c345655a0149f64c5020bfc1e53c619ce60587f6

2) The latest way of using pflash devices in other architectures and libvirt
is by using -blockdev and machine options. However, currently this method is
not working in RISC-V.

With above issues fixed, added documentation on how to use pflash devices
in RISC-V virt machine.

This patch series is based on Alistair's riscv-to-apply.next branch.

Changes since v6:
	1) Updated the documentation patch as per text provided by Andrea.

Changes since v5:
	1) Added KVM use case as per feedback from Anup. Updated the documentation
	   patch that only S-mode payload is supported for KVM guests. Tested with
	   KVM enabled.
	2) Updated tags.

Changes since v4:
	1) Updated patch 2 to avoid accessing private field as per feedback from Philippe.
	2) Updated documentation patch to add read-only for ROM usage.
	3) Rebased to latest riscv-to-apply.next branch and updated tags.

Changes since v3:
	1) Converted single patch to a series with a cover letter since there are
	   multiple patches now.
	2) Added a new patch to enable pflash usage via -blockdev option.
	3) Separated the documentation change into new patch and updated the
	   documentation to mention only -blockdev option which seems to be the
	   recommended way of using pflash.

Changes since v2:
	1) Reverted v2 changes and used v1 approach so that pflash0 can be used
	   for code and pflash1 for variable store.
	2) Rebased to latest riscv-to-apply.next branch.
	3) Added documentation for pflash usage.

Changes since v1:
	1) Simplified the fix such that it doesn't break current EDK2.

Sunil V L (3):
  hw/riscv: virt: Assume M-mode FW in pflash0 only when "-bios none"
  riscv/virt: Support using pflash via -blockdev option
  docs/system: riscv: Add pflash usage details

 docs/system/riscv/virt.rst | 31 ++++++++++++++++++++
 hw/riscv/virt.c            | 59 ++++++++++++++++----------------------
 2 files changed, 56 insertions(+), 34 deletions(-)

Comments

Alistair Francis June 2, 2023, 2:11 a.m. UTC | #1

On Thu, Jun 1, 2023 at 3:00 PM Sunil V L <[e-mail]> wrote:
>
> This series improves the pflash usage in RISC-V virt machine with solutions to
> below issues.
>
> 1) Currently the first pflash is reserved for ROM/M-mode firmware code. But S-mode
> payload firmware like EDK2 need both pflash devices to have separate code and variable
> store so that OS distros can keep the FW code as read-only.
>
> The issue is reported at
> https://salsa.debian.org/qemu-team/edk2/-/commit/c345655a0149f64c5020bfc1e53c619ce60587f6
>
> 2) The latest way of using pflash devices in other architectures and libvirt
> is by using -blockdev and machine options. However, currently this method is
> not working in RISC-V.
>
> With above issues fixed, added documentation on how to use pflash devices
> in RISC-V virt machine.
>
> This patch series is based on Alistair's riscv-to-apply.next branch.
>
> Changes since v6:
>         1) Updated the documentation patch as per text provided by Andrea.
>
> Changes since v5:
>         1) Added KVM use case as per feedback from Anup. Updated the documentation
>            patch that only S-mode payload is supported for KVM guests. Tested with
>            KVM enabled.
>         2) Updated tags.
>
> Changes since v4:
>         1) Updated patch 2 to avoid accessing private field as per feedback from Philippe.
>         2) Updated documentation patch to add read-only for ROM usage.
>         3) Rebased to latest riscv-to-apply.next branch and updated tags.
>
> Changes since v3:
>         1) Converted single patch to a series with a cover letter since there are
>            multiple patches now.
>         2) Added a new patch to enable pflash usage via -blockdev option.
>         3) Separated the documentation change into new patch and updated the
>            documentation to mention only -blockdev option which seems to be the
>            recommended way of using pflash.
>
> Changes since v2:
>         1) Reverted v2 changes and used v1 approach so that pflash0 can be used
>            for code and pflash1 for variable store.
>         2) Rebased to latest riscv-to-apply.next branch.
>         3) Added documentation for pflash usage.
>
> Changes since v1:
>         1) Simplified the fix such that it doesn't break current EDK2.
>
> Sunil V L (3):
>   hw/riscv: virt: Assume M-mode FW in pflash0 only when "-bios none"
>   riscv/virt: Support using pflash via -blockdev option
>   docs/system: riscv: Add pflash usage details

Thanks!

Applied to riscv-to-apply.next

Alistair

>
>  docs/system/riscv/virt.rst | 31 ++++++++++++++++++++
>  hw/riscv/virt.c            | 59 ++++++++++++++++----------------------
>  2 files changed, 56 insertions(+), 34 deletions(-)
>
> --
> 2.34.1
>
>