From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=49100 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PzxaT-0007xj-QX for qemu-devel@nongnu.org; Wed, 16 Mar 2011 16:44:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PzxaS-0003mV-Cd for qemu-devel@nongnu.org; Wed, 16 Mar 2011 16:44:57 -0400 Received: from mail-iy0-f173.google.com ([209.85.210.173]:62573) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PzxaS-0003mR-8G for qemu-devel@nongnu.org; Wed, 16 Mar 2011 16:44:56 -0400 Received: by iym7 with SMTP id 7so2349495iym.4 for ; Wed, 16 Mar 2011 13:44:55 -0700 (PDT) Message-ID: <4D812141.60402@codemonkey.ws> Date: Wed, 16 Mar 2011 15:44:49 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 03/26] Add a hook to allow hypercalls to be emulated on PowerPC References: <1300251423-6715-1-git-send-email-david@gibson.dropbear.id.au> <1300251423-6715-4-git-send-email-david@gibson.dropbear.id.au> In-Reply-To: <1300251423-6715-4-git-send-email-david@gibson.dropbear.id.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: paulus@samba.org, agraf@suse.de, anton@samba.org, qemu-devel@nongnu.org On 03/15/2011 11:56 PM, David Gibson wrote: > From: David Gibson > > PowerPC and POWER chips since the POWER4 and 970 have a special > hypervisor mode, and a corresponding form of the system call > instruction which traps to the hypervisor. > > qemu currently has stub implementations of hypervisor mode. That > is, the outline is there to allow qemu to run a PowerPC hypervisor > under emulation. There are a number of details missing so this > won't actually work at present, but the idea is there. > > What there is no provision at all, is for qemu to instead emulate > the hypervisor itself. That is to have hypercalls trap into qemu > and their result be emulated from qemu, rather than running > hypervisor code within the emulated system. > > Hypervisor hardware aware KVM implementations are in the works and > it would be useful for debugging and development to also allow > full emulation of the same para-virtualized guests as such a KVM. > > Therefore, this patch adds a hook which will allow a machine to > set up emulation of hypervisor calls. > > Signed-off-by: David Gibson > --- > target-ppc/cpu.h | 2 ++ > target-ppc/helper.c | 4 ++++ > 2 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h > index a20c132..eaddc27 100644 > --- a/target-ppc/cpu.h > +++ b/target-ppc/cpu.h > @@ -692,6 +692,8 @@ struct CPUPPCState { > int bfd_mach; > uint32_t flags; > uint64_t insns_flags; > + void (*emulate_hypercall)(CPUState *, void *); > + void *hcall_opaque; Is the hypercall handler ever specific to a CPU? I'd prefer to see this as a generic interface that wasn't specific to target-ppc. Basically, add a: void cpu_hypercall(CPUState *env); And then implement it within your target. I'm not sure I get the opaque argument. Regards, Anthony Liguori > > int error_code; > uint32_t pending_interrupts; > diff --git a/target-ppc/helper.c b/target-ppc/helper.c > index 2094ca3..19aa067 100644 > --- a/target-ppc/helper.c > +++ b/target-ppc/helper.c > @@ -2152,6 +2152,10 @@ static inline void powerpc_excp(CPUState *env, int excp_model, int excp) > case POWERPC_EXCP_SYSCALL: /* System call exception */ > dump_syscall(env); > lev = env->error_code; > + if ((lev == 1)&& env->emulate_hypercall) { > + env->emulate_hypercall(env, env->hcall_opaque); > + return; > + } > if (lev == 1 || (lpes0 == 0&& lpes1 == 0)) > new_msr |= (target_ulong)MSR_HVB; > goto store_next;