From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Tue, 10 Dec 2013 14:27:07 -0800 Subject: [PATCH 1/2] KVM: Add KVM_EXIT_RESET to user space API header In-Reply-To: References: <1385394599-15439-1-git-send-email-anup.patel@linaro.org> <1385394599-15439-2-git-send-email-anup.patel@linaro.org> Message-ID: <20131210222707.GA2871@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Dec 10, 2013 at 03:13:34AM +0100, Alexander Graf wrote: > > On 25.11.2013, at 16:49, Anup Patel wrote: > > > Currently, we don't have an exit reason for VM reset emulation > > in user space hence this patch adds exit reason KVM_EXIT_RESET > > for this purpose. > > > > This newly added KVM_EXIT_RESET will be used by KVM arm/arm64 > > in-kernel PSCI support to reset VMs. > > > > Signed-off-by: Anup Patel > > Signed-off-by: Pranavkumar Sawargaonkar > > --- > > include/uapi/linux/kvm.h | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index 902f124..64a04cc 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -171,6 +171,7 @@ struct kvm_pit_config { > > #define KVM_EXIT_WATCHDOG 21 > > #define KVM_EXIT_S390_TSCH 22 > > #define KVM_EXIT_EPR 23 > > +#define KVM_EXIT_RESET 24 > > I have to admit that I'm not particularly happy with the exit name. It's not obvious from the name under which circumstances it gets triggered. Does it get triggered when a core level reset happens? Does it get triggered when a system level reset happened? When the guest requests one? > > I know what it does, but I find the name too generic for what it is. What you're really doing is introduce a new communication channel in parallel to MMIO / PIO / HCALL which is only used for system level reset / shutdown today. > > Can we treat it as such? Could you please make this a common exit number that's called something like > > KVM_EXIT_SYSTEM_EVENT > > with a parameter that can either be TRIGGER_SHUTDOWN or TRIGGER_RESET. > > That way it's obvious what's going on and people don't get confused. > I didn't realize what the KVM_EXIT_SHUTDOWN really was, thanks for explaining that. In that case, the SYSTEM_EVENT sounds good to me. How do you propose the parameter gets passed? As a new struct to the untion in kvm_run ? -Christoffer