Re: [PATCH 5/5] powerpc: using reset hcall when kvm,has-reset

Alexander Graf
2013-07-15T11:50:18Z

On 15.07.2013, at 13:11, Bharat Bhushan wrote:

> Detect the availability of the reset hcalls by looking at kvm,has-reset
> property on the /hypervisor node in the device tree passed to the VM and
> patches the reset mechanism to use reset hcall.
>
> This patch uses the reser hcall when kvm,has-reset is there in

Your patch description is pretty broken :).

>
> Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
> ---
> arch/powerpc/kernel/epapr_paravirt.c | 12 ++++++++++++
> 1 files changed, 12 insertions(+), 0 deletions(-)
>
> diff --git a/arch/powerpc/kernel/epapr_paravirt.c b/arch/powerpc/kernel/epapr_paravirt.c
> index d44a571..651d701 100644
> --- a/arch/powerpc/kernel/epapr_paravirt.c
> +++ b/arch/powerpc/kernel/epapr_paravirt.c
> @@ -22,6 +22,8 @@
> #include <asm/cacheflush.h>
> #include <asm/code-patching.h>
> #include <asm/machdep.h>
> +#include <asm/kvm_para.h>
> +#include <asm/kvm_host.h>

Why would we need kvm_host.h? This is guest code.

>
> #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
> extern void epapr_ev_idle(void);
> @@ -30,6 +32,14 @@ extern u32 epapr_ev_idle_start[];
>
> bool epapr_paravirt_enabled;
>
> +void epapr_hypercall_reset(char *cmd)
> +{
> + long ret;
> + ret = kvm_hypercall0(KVM_HC_VM_RESET);

Is this available without CONFIG_KVM_GUEST? kvm_hypercall() simply returns "unimplemented" for everything when that config option is not set.

> + printk("error: system reset returned with error %ld\n", ret);

So we should fall back to the normal reset handler here.

Alex

> + BUG();
> +}
> +
> static int __init epapr_paravirt_init(void)
> {
> struct device_node *hyper_node;
> @@ -58,6 +68,8 @@ static int __init epapr_paravirt_init(void)
> if (of_get_property(hyper_node, "has-idle", NULL))
> ppc_md.power_save = epapr_ev_idle;
> #endif
> + if (of_get_property(hyper_node, "kvm,has-reset", NULL))
> + ppc_md.restart = epapr_hypercall_reset;
>
> epapr_paravirt_enabled = true;
>
> --
> 1.7.0.4
>
>
> --
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