[SeaBIOS] [Qemu-devel][PATCH] SeaBios: Fix reset procedure reentrancy problem on qemu-kvm platform

[Gonglei]

Ccing Seabios community.

On 2015/11/3 14:58, Xulei (Stone, Euler) wrote:
> On qemu-kvm platform, when I reset a VM through "virsh reset", and coincidently
> the VM is in process of internal rebooting at the same time. Then the VM will
> not be successfully reseted any more due to the reset reentrancy. I found:
> (1)SeaBios try to shutdown the VM after reseting it failed by apm_shutdown().
> However, apm_shutdown() does not work on qemu-kvm platform;
> (2)I add 1s sleep in qemu_prep_reset(), then continuously reset the VM twice,
> aforementioned case must happen.
> This patch fixes this issue by letting the VM always execute the reboot
> routing while a reenrancy happenes instead of attempting apm_shutdown on
> qemu-kvm platform.
> 
> Signed-off-by: Lei Xu <stone.xulei at huawei.com>
> ---
>   roms/seabios/src/resume.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/roms/seabios/src/resume.c b/roms/seabios/src/resume.c
> index 1903174..96ff79e 100644
> --- a/roms/seabios/src/resume.c
> +++ b/roms/seabios/src/resume.c
> @@ -16,6 +16,7 @@
>   #include "std/bda.h" // struct bios_data_area_s
>   #include "string.h" // memset
>   #include "util.h" // dma_setup
> +#include "fw/paravirt.h" //runningOnKVM
> 
>   // Handler for post calls that look like a resume.
>   void VISIBLE16
> @@ -122,7 +123,11 @@ tryReboot(void)
>           dprintf(1, "Unable to hard-reboot machine - attempting shutdown.\n");
>           apm_shutdown();
>       }
> -    HaveAttemptedReboot = 1;
> +    if (!runningOnKVM()) {
> +        // Hard reboot has failed - try to shutdown machine.
> +        HaveAttemptedReboot = 1;
> +    }
> +
> 
>       dprintf(1, "Attempting a hard reboot\n");
> 
> --
> 1.7.12.4
>