From: Simon Guo <wei.guo.simon@gmail.com>
To: Paul Mackerras <paulus@ozlabs.org>
Cc: linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 04/26] KVM: PPC: Book3S PR: add C function wrapper for _kvmppc_save/restore_tm()
Date: Tue, 30 Jan 2018 10:38:33 +0800 [thread overview]
Message-ID: <20180130023833.GC3261@simonLocalRHEL7.x64> (raw)
In-Reply-To: <20180123054916.GC3924@fergus.ozlabs.ibm.com>
Hi Paul,
On Tue, Jan 23, 2018 at 04:49:16PM +1100, Paul Mackerras wrote:
> On Thu, Jan 11, 2018 at 06:11:17PM +0800, wei.guo.simon@gmail.com wrote:
> > From: Simon Guo <wei.guo.simon@gmail.com>
> >
> > Currently _kvmppc_save/restore_tm() APIs can only be invoked from
> > assembly function. This patch adds C function wrappers for them so
> > that they can be safely called from C function.
> >
> > Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
>
> [snip]
>
> > --- a/arch/powerpc/include/asm/asm-prototypes.h
> > +++ b/arch/powerpc/include/asm/asm-prototypes.h
> > @@ -126,4 +126,11 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
> > void _mcount(void);
> > unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip);
> >
> > +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> > +/* Transaction memory related */
> > +struct kvm_vcpu;
> > +void _kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu, u64 guest_msr);
> > +void _kvmppc_save_tm_pr(struct kvm_vcpu *vcpu, u64 guest_msr);
> > +#endif
>
> It's not generally necessary to have ifdefs around function
> declarations. If the function is never defined because the feature
> is not configured in, that is fine.
>
Got it. Thanks.
> > @@ -149,6 +149,58 @@ _GLOBAL(kvmppc_save_tm)
> > blr
> >
> > /*
> > + * _kvmppc_save_tm() is a wrapper around __kvmppc_save_tm(), so that it can
> > + * be invoked from C function by PR KVM only.
> > + */
> > +_GLOBAL(_kvmppc_save_tm_pr)
> > + mflr r5
> > + std r5, PPC_LR_STKOFF(r1)
> > + stdu r1, -SWITCH_FRAME_SIZE(r1)
> > + SAVE_NVGPRS(r1)
> > +
> > + /* save MSR since TM/math bits might be impacted
> > + * by __kvmppc_save_tm().
> > + */
> > + mfmsr r5
> > + SAVE_GPR(5, r1)
> > +
> > + /* also save DSCR/CR so that it can be recovered later */
> > + mfspr r6, SPRN_DSCR
> > + SAVE_GPR(6, r1)
> > +
> > + mfcr r7
> > + stw r7, _CCR(r1)
> > +
> > + /* allocate stack frame for __kvmppc_save_tm since
> > + * it will save LR into its stackframe and we don't
> > + * want to corrupt _kvmppc_save_tm_pr's.
> > + */
> > + stdu r1, -PPC_MIN_STKFRM(r1)
>
> You don't need to do this. In the PowerPC ELF ABI, functions always
> save their LR (i.e. their return address) in their *caller's* stack
> frame, not their own. You have established a stack frame for
> _kvmppc_save_tm_pr above, and that is sufficient. Same comment
> applies for _kvmppc_restore_tm_pr.
Ah..yes. I need remove that.
Thanks,
- Simon
next prev parent reply other threads:[~2018-01-30 2:38 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-11 10:11 [PATCH 00/26] KVM: PPC: Book3S PR: Transaction memory support on PR KVM wei.guo.simon
2018-01-11 10:11 ` [PATCH 01/26] KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate file wei.guo.simon
2018-01-11 10:11 ` [PATCH 02/26] KVM: PPC: Book3S PR: add new parameter (guest MSR) for kvmppc_save_tm()/kvmppc_restore_tm() wei.guo.simon
2018-01-23 5:42 ` Paul Mackerras
2018-01-30 2:33 ` Simon Guo
2018-01-11 10:11 ` [PATCH 03/26] KVM: PPC: Book3S PR: turn on FP/VSX/VMX MSR bits in kvmppc_save_tm() wei.guo.simon
2018-01-11 10:11 ` [PATCH 04/26] KVM: PPC: Book3S PR: add C function wrapper for _kvmppc_save/restore_tm() wei.guo.simon
2018-01-23 5:49 ` Paul Mackerras
2018-01-30 2:38 ` Simon Guo [this message]
2018-01-11 10:11 ` [PATCH 05/26] KVM: PPC: Book3S PR: In PR KVM suspends Transactional state when inject an interrupt wei.guo.simon
2018-01-11 10:11 ` [PATCH 06/26] KVM: PPC: Book3S PR: PR KVM pass through MSR TM/TS bits to shadow_msr wei.guo.simon
2018-01-11 10:11 ` [PATCH 07/26] KVM: PPC: Book3S PR: add TEXASR related macros wei.guo.simon
2018-01-23 5:50 ` Paul Mackerras
2018-01-11 10:11 ` [PATCH 08/26] KVM: PPC: Book3S PR: Sync TM bits to shadow msr for problem state guest wei.guo.simon
2018-01-11 10:11 ` [PATCH 09/26] KVM: PPC: Book3S PR: implement RFID TM behavior to suppress change from S0 to N0 wei.guo.simon
2018-01-11 10:11 ` [PATCH 10/26] KVM: PPC: Book3S PR: set MSR HV bit accordingly for PPC970 and others wei.guo.simon
2018-01-23 5:51 ` Paul Mackerras
2018-01-11 10:11 ` [PATCH 11/26] KVM: PPC: Book3S PR: prevent TS bits change in kvmppc_interrupt_pr() wei.guo.simon
2018-01-11 10:11 ` [PATCH 12/26] powerpc: export symbol msr_check_and_set() wei.guo.simon
2018-01-11 10:11 ` [PATCH 13/26] KVM: PPC: Book3S PR: adds new kvmppc_copyto_vcpu_tm/kvmppc_copyfrom_vcpu_tm API for PR KVM wei.guo.simon
2018-01-23 5:52 ` Paul Mackerras
2018-01-30 2:15 ` Simon Guo
2018-01-11 10:11 ` [PATCH 14/26] KVM: PPC: Book3S PR: export tm_enable()/tm_disable/tm_abort() APIs wei.guo.simon
2018-01-11 10:11 ` [PATCH 15/26] KVM: PPC: Book3S PR: add kvmppc_save/restore_tm_sprs() APIs wei.guo.simon
2018-01-11 10:11 ` [PATCH 16/26] KVM: PPC: Book3S PR: add transaction memory save/restore skeleton for PR KVM wei.guo.simon
2018-01-23 6:04 ` Paul Mackerras
2018-01-30 2:57 ` Simon Guo
2018-01-11 10:11 ` [PATCH 17/26] KVM: PPC: Book3S PR: add math support for PR KVM HTM wei.guo.simon
2018-01-23 7:29 ` Paul Mackerras
2018-01-30 3:00 ` Simon Guo
2018-01-11 10:11 ` [PATCH 18/26] KVM: PPC: Book3S PR: make mtspr/mfspr emulation behavior based on active TM SPRs wei.guo.simon
2018-01-23 8:17 ` Paul Mackerras
2018-01-30 3:02 ` Simon Guo
2018-01-11 10:11 ` [PATCH 19/26] KVM: PPC: Book3S PR: always fail transaction in guest privilege state wei.guo.simon
2018-01-23 8:30 ` Paul Mackerras
2018-01-30 3:11 ` Simon Guo
2018-01-11 10:11 ` [PATCH 20/26] KVM: PPC: Book3S PR: enable NV reg restore for reading TM SPR at " wei.guo.simon
2018-01-23 9:08 ` Paul Mackerras
2018-01-11 10:11 ` [PATCH 21/26] KVM: PPC: Book3S PR: adds emulation for treclaim wei.guo.simon
2018-01-23 9:23 ` Paul Mackerras
2018-01-30 3:18 ` Simon Guo
2018-01-11 10:11 ` [PATCH 22/26] KVM: PPC: Book3S PR: add emulation for trechkpt in PR KVM wei.guo.simon
2018-01-23 9:36 ` Paul Mackerras
2018-01-30 3:13 ` Simon Guo
2018-01-11 10:11 ` [PATCH 23/26] KVM: PPC: Book3S PR: add emulation for tabort. for privilege guest wei.guo.simon
2018-01-23 9:44 ` Paul Mackerras
2018-01-30 3:24 ` Simon Guo
2018-01-11 10:11 ` [PATCH 24/26] KVM: PPC: Book3S PR: add guard code to prevent returning to guest with PR=0 and Transactional state wei.guo.simon
2018-01-11 10:11 ` [PATCH 25/26] KVM: PPC: Book3S PR: Support TAR handling for PR KVM HTM wei.guo.simon
2018-01-24 4:02 ` Paul Mackerras
2018-01-30 3:26 ` Simon Guo
2018-01-11 10:11 ` [PATCH 26/26] KVM: PPC: Book3S PR: enable HTM for PR KVM for KVM_CHECK_EXTENSION ioctl wei.guo.simon
2018-01-11 13:56 ` [PATCH 00/26] KVM: PPC: Book3S PR: Transaction memory support on PR KVM Gustavo Romero
2018-01-11 22:04 ` Benjamin Herrenschmidt
2018-01-12 2:41 ` Simon Guo
2018-01-23 5:38 ` Paul Mackerras
2018-01-23 7:16 ` Paul Mackerras
2018-01-27 13:10 ` Simon Guo
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