Re: [PATCH 5/6] pvpanic : update pvpanic document

[Peter Maydell]

On Wed, 28 Oct 2020 at 14:26, Mihai Carabas <mihai.carabas@oracle.com> wrote:
>
> From: Peng Hao <peng.hao2@zte.com.cn>
>
> Add mmio mode as a pci device support info in docs/specs/pvpanic.txt.
>
> Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
> Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
> ---
>  docs/specs/pvpanic.txt | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/docs/specs/pvpanic.txt b/docs/specs/pvpanic.txt
> index a90fbca..4258922 100644
> --- a/docs/specs/pvpanic.txt
> +++ b/docs/specs/pvpanic.txt
> @@ -1,7 +1,7 @@
>  PVPANIC DEVICE
>  ==============
>
> -pvpanic device is a simulated ISA device, through which a guest panic
> +pvpanic device is a simulated device, through which a guest panic
>  event is sent to qemu, and a QMP event is generated. This allows
>  management apps (e.g. libvirt) to be notified and respond to the event.
>
> @@ -9,6 +9,9 @@ The management app has the option of waiting for 
> GUEST_PANICKED events,
>  and/or polling for guest-panicked RunState, to learn when the pvpanic
>  device has fired a panic event.
>
> +The pvpanic device can be implemented as an ISA device (using IOPORT),
> +or, since qemu 4.0, as a PCI device.

Version number is outdated here. I would simply say "or as a PCI device".

> +
>  ISA Interface
>  -------------
>
> @@ -24,6 +27,13 @@ bit 1: a guest panic has happened and will be handled by 
> the guest;
>         the host should record it or report it, but should not affect
>         the execution of the guest.
>
> +PCI Interface
> +-------------
> +
> +The PCI interface is similar to the ISA interface except that it uses an MMIO
> +address space provided by its BAR0.

You should be specific about the access width(s) permitted here --
is the access to the register 8-bit only, 32-bit-only, or what ?

> For example, the arm virt machine may
> +enable a pvpanic device by adding '-device pvpanic-pci' to the command line.

No need to be specific to Arm virt here.
"Any machine with a PCI device can enable a pvpanic device by adding
'-device pvpanic-pci' to the command line."


> +
>  ACPI Interface
>  --------------

thanks
-- PMM