On Mon, Aug 22, 2016 at 05:37:49PM -0500, Tom Lendacky wrote: > This patch adds support to be change the memory encryption attribute for > one or more memory pages. > > Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx> > --- > arch/x86/include/asm/cacheflush.h | 3 + > arch/x86/include/asm/mem_encrypt.h | 13 ++++++ > arch/x86/mm/mem_encrypt.c | 43 +++++++++++++++++++++ > arch/x86/mm/pageattr.c | 75 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 134 insertions(+) ... > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c > index 72c292d..0ba9382 100644 > --- a/arch/x86/mm/pageattr.c > +++ b/arch/x86/mm/pageattr.c > @@ -1728,6 +1728,81 @@ int set_memory_4k(unsigned long addr, int numpages) > __pgprot(0), 1, 0, NULL); > } > > +static int __set_memory_enc_dec(struct cpa_data *cpa) > +{ > + unsigned long addr; > + int numpages; > + int ret; > + > + if (*cpa->vaddr & ~PAGE_MASK) { > + *cpa->vaddr &= PAGE_MASK; > + > + /* People should not be passing in unaligned addresses */ > + WARN_ON_ONCE(1); Let's make this more user-friendly: if (WARN_ONCE(*cpa->vaddr & ~PAGE_MASK, "Misaligned address: 0x%lx\n", *cpa->vaddr)) *cpa->vaddr &= PAGE_MASK; > + } > + > + addr = *cpa->vaddr; > + numpages = cpa->numpages; > + > + /* Must avoid aliasing mappings in the highmem code */ > + kmap_flush_unused(); > + vm_unmap_aliases(); > + > + ret = __change_page_attr_set_clr(cpa, 1); > + > + /* Check whether we really changed something */ > + if (!(cpa->flags & CPA_FLUSHTLB)) > + goto out; > + > + /* > + * On success we use CLFLUSH, when the CPU supports it to > + * avoid the WBINVD. > + */ > + if (!ret && static_cpu_has(X86_FEATURE_CLFLUSH)) > + cpa_flush_range(addr, numpages, 1); > + else > + cpa_flush_all(1); So if we fail (ret != 0) we do WBINVD unconditionally even if we don't have to? Don't you want this instead: ret = __change_page_attr_set_clr(cpa, 1); if (ret) goto out; /* Check whether we really changed something */ if (!(cpa->flags & CPA_FLUSHTLB)) goto out; /* * On success we use CLFLUSH, when the CPU supports it to * avoid the WBINVD. */ if (static_cpu_has(X86_FEATURE_CLFLUSH)) cpa_flush_range(addr, numpages, 1); else cpa_flush_all(1); out: return ret; } ? -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html