| Message ID | 1524657284-16706-5-git-send-email-wei.guo.simon@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | KVM: PPC: reconstruct mmio emulation with analyse_instr() | expand |
On Wed, Apr 25, 2018 at 07:54:37PM +0800, wei.guo.simon@gmail.com wrote: > From: Simon Guo <wei.guo.simon@gmail.com> > > stwsiwx will place contents of word element 1 of VSR into word > storage of EA. So the element size of stwsiwx should be 4. > > This patch correct the size from 8 to 4. > > Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> > --- > arch/powerpc/lib/sstep.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c > index 34d68f1..151d484 100644 > --- a/arch/powerpc/lib/sstep.c > +++ b/arch/powerpc/lib/sstep.c > @@ -2178,7 +2178,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, > case 140: /* stxsiwx */ > op->reg = rd | ((instr & 1) << 5); > op->type = MKOP(STORE_VSX, 0, 4); > - op->element_size = 8; > + op->element_size = 4; I made the element_size be 8 deliberately because this way, with size=4 but element_size=8, the code will naturally choose the correct word (the least-significant word of the left half) of the register to store into memory. With this change you then need the special case in a later patch for stxsiwx, which you shouldn't need if you don't make this change. Paul.
On Thu, May 03, 2018 at 03:50:47PM +1000, Paul Mackerras wrote: > On Wed, Apr 25, 2018 at 07:54:37PM +0800, wei.guo.simon@gmail.com wrote: > > From: Simon Guo <wei.guo.simon@gmail.com> > > > > stwsiwx will place contents of word element 1 of VSR into word > > storage of EA. So the element size of stwsiwx should be 4. > > > > This patch correct the size from 8 to 4. > > > > Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> > > --- > > arch/powerpc/lib/sstep.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c > > index 34d68f1..151d484 100644 > > --- a/arch/powerpc/lib/sstep.c > > +++ b/arch/powerpc/lib/sstep.c > > @@ -2178,7 +2178,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, > > case 140: /* stxsiwx */ > > op->reg = rd | ((instr & 1) << 5); > > op->type = MKOP(STORE_VSX, 0, 4); > > - op->element_size = 8; > > + op->element_size = 4; > > I made the element_size be 8 deliberately because this way, with > size=4 but element_size=8, the code will naturally choose the correct > word (the least-significant word of the left half) of the register to > store into memory. With this change you then need the special case in > a later patch for stxsiwx, which you shouldn't need if you don't make > this change. > > Paul. Thanks for point out. I will update accordingly. Thanks, - Simon
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 34d68f1..151d484 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -2178,7 +2178,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, case 140: /* stxsiwx */ op->reg = rd | ((instr & 1) << 5); op->type = MKOP(STORE_VSX, 0, 4); - op->element_size = 8; + op->element_size = 4; break; case 268: /* lxvx */