> -----Original Message----- > From: Alexander Graf [mailto:agraf@xxxxxxx] > Sent: Monday, July 15, 2013 8:40 PM > To: Bhushan Bharat-R65777 > Cc: kvm@xxxxxxxxxxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; Wood Scott-B07421; Yoder > Stuart-B08248 > Subject: Re: [PATCH 5/5] powerpc: using reset hcall when kvm,has-reset > > > On 15.07.2013, at 17:05, Bhushan Bharat-R65777 wrote: > > > > > > >> -----Original Message----- > >> From: Alexander Graf [mailto:agraf@xxxxxxx] > >> Sent: Monday, July 15, 2013 5:20 PM > >> To: Bhushan Bharat-R65777 > >> Cc: kvm@xxxxxxxxxxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; Wood Scott-B07421; > >> Yoder Stuart-B08248; Bhushan Bharat-R65777 > >> Subject: Re: [PATCH 5/5] powerpc: using reset hcall when > >> kvm,has-reset > >> > >> > >> 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@xxxxxxxxxxxxx> > >>> --- > >>> 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. > > > > We are here because we patched the ppc_md.restart to point to new handler. > > So I think we should patch the ppc_md.restart only if CONFIG_KVM_GUEST is > true. > > We should only patch it if kvm_para_available(). That should guard us against > everything. > > > > > > >> > >>> + printk("error: system reset returned with error %ld\n", ret); > >> > >> So we should fall back to the normal reset handler here. > > > > Do you mean return normally from here, no BUG() etc? > > If we guard the patching against everything, we can treat a broken hcall as BUG. > However, if we don't we want to fall back to the normal guts based reset. Will let Scott comment on this? But ppc_md.restart can point to only one handler and during paravirt patching we changed this to new handler. So we cannot jump back to guts type handler -Bharat -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
