Re: [RFC PATCH v3 07/38] xen-platform: allow its creation with XEN_EMULATE mode

[Paul Durrant]

On 16/12/2022 00:40, David Woodhouse wrote:
> From: Joao Martins <joao.m.martins@oracle.com>
>
> The only thing we need to handle on KVM side is to change the
> pfn from R/W to R/O.
>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
>   hw/i386/xen/xen_platform.c | 11 ++++-------
>   1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
> index a6f0fb478a..15d5ae7c69 100644
> --- a/hw/i386/xen/xen_platform.c
> +++ b/hw/i386/xen/xen_platform.c
> @@ -283,7 +283,10 @@ static void platform_fixed_ioport_writeb(void *opaque, 
> uint32_t addr, uint32_t v
>       case 0: /* Platform flags */ {
>           hvmmem_type_t mem_type = (val & PFFLAG_ROM_LOCK) ?
>               HVMMEM_ram_ro : HVMMEM_ram_rw;
> -        if (xen_set_mem_type(xen_domid, mem_type, 0xc0, 0x40)) {
> +        if (xen_mode == XEN_EMULATE) {
> +            /* XXX */

???

Paul

> +            s->flags = val & PFFLAG_ROM_LOCK;
> +        } else if (xen_set_mem_type(xen_domid, mem_type, 0xc0, 0x40)) {
>               DPRINTF("unable to change ro/rw state of ROM memory area!\n");
>           } else {
>               s->flags = val & PFFLAG_ROM_LOCK;
> @@ -508,12 +511,6 @@ static void xen_platform_realize(PCIDevice *dev, Error 
> **errp)
>       PCIXenPlatformState *d = XEN_PLATFORM(dev);
>       uint8_t *pci_conf;
>   
> -    /* Device will crash on reset if xen is not initialized */
> -    if (!xen_enabled()) {
> -        error_setg(errp, "xen-platform device requires the Xen accelerator");
> -        return;
> -    }
> -
>       pci_conf = dev->config;
>   
>       pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_IO | PCI_COMMAND_MEMORY);