Hi Radim, Radim Krčmář <rkrcmar@xxxxxxxxxx> writes: ... > static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, > @@ -704,7 +708,7 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, > } > break; > } > - if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0)) > + if (la & (insn_alignment(ctxt, size) - 1)) > return emulate_gp(ctxt, 0); > return X86EMUL_CONTINUE; > bad: > @@ -3856,6 +3860,75 @@ static int em_movsxd(struct x86_emulate_ctxt *ctxt) > return X86EMUL_CONTINUE; > } > > +static int check_fxsr(struct x86_emulate_ctxt *ctxt) > +{ > + u32 eax = 1, ebx, ecx = 0, edx; > + > + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); > + if (!(edx & FFL(FXSR))) > + return emulate_ud(ctxt); > + > + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) > + return emulate_nm(ctxt); > + > + return X86EMUL_CONTINUE; > +} > + > +/* > + * FXSAVE and FXRSTOR have 3 different formats depending on execution mode, > + * 1) non-64-bit mode > + * 2) 64-bit mode with REX.W prefix > + * 3) 64-bit mode without REX.W prefix > + * > + * Emulation uses (3) for for (1) mode because only the number of XMM registers > + * is different. > + */ > +static int em_fxsave(struct x86_emulate_ctxt *ctxt) > +{ > + char fx_state[512] __aligned(16); > + int rc; > + > + rc = check_fxsr(ctxt); > + if (rc != X86EMUL_CONTINUE) > + return rc; > + > + ctxt->ops->get_fpu(ctxt); > +#ifdef CONFIG_X86_64 > + if (ctxt->rex_prefix & (1 << 3)) > + asm volatile("fxsave64 %0" : "+m"(fx_state)); > + else > +#endif > + asm volatile("fxsave %0" : "+m"(fx_state)); > + ctxt->ops->put_fpu(ctxt); > + > + return segmented_write(ctxt, ctxt->memop.addr.mem, fx_state, 512); > +} > + > +static int em_fxrstor(struct x86_emulate_ctxt *ctxt) > +{ > + char fx_state[512] __aligned(16); > + int rc; > + > + rc = check_fxsr(ctxt); Is this check enough here ? What I mean is that is it possible that the memory image that is read from has data in an invalid format/corrupt or is that irrelevant ? Bandan > + if (rc != X86EMUL_CONTINUE) > + return rc; > + > + rc = segmented_read(ctxt, ctxt->memop.addr.mem, fx_state, 512); > + if (rc != X86EMUL_CONTINUE) > + return rc; > + > + ctxt->ops->get_fpu(ctxt); > +#ifdef CONFIG_X86_64 > + if (ctxt->rex_prefix & (1 << 3)) > + asm volatile("fxrstor64 %0" : "+m"(fx_state)); > + else > +#endif > + asm volatile("fxrstor %0" : "+m"(fx_state)); > + ctxt->ops->put_fpu(ctxt); > + > + return X86EMUL_CONTINUE; > +} > + > static bool valid_cr(int nr) > { > switch (nr) { > @@ -4208,7 +4281,9 @@ static const struct gprefix pfx_0f_ae_7 = { > }; > > static const struct group_dual group15 = { { > - N, N, N, N, N, N, N, GP(0, &pfx_0f_ae_7), > + I(ModRM | Aligned16, em_fxsave), > + I(ModRM | Aligned16, em_fxrstor), > + N, N, N, N, N, GP(0, &pfx_0f_ae_7), > }, { > N, N, N, N, N, N, N, N, > } }; -- 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