On July 10, 2018 6:49:10 AM EDT, "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote:
>On Mon, Jul 09, 2018 at 02:20:55PM -0400, Konrad Rzeszutek Wilk wrote:
>> On Tue, Jun 26, 2018 at 05:22:40PM +0300, Kirill A. Shutemov wrote:
>> > The new helper mktme_disable() allows to disable MKTME even if it's
>> > enumerated successfully. MKTME initialization may fail and this
>> > functionality allows system to boot regardless of the failure.
>> >
>> > MKTME needs per-KeyID direct mapping. It requires a lot more
>virtual
>> > address space which may be a problem in 4-level paging mode. If the
>> > system has more physical memory than we can handle with MKTME.
>>
>> .. then what should happen?
>
>We fail MKTME initialization and boot the system. See next sentence.
Perhaps you can then remove the "." and join the sentences
>
>> > The feature allows to fail MKTME, but boot the system successfully.
>> >
>> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
>> > ---
>> > arch/x86/include/asm/mktme.h | 2 ++
>> > arch/x86/kernel/cpu/intel.c | 5 +----
>> > arch/x86/mm/mktme.c | 9 +++++++++
>> > 3 files changed, 12 insertions(+), 4 deletions(-)
>> >
>> > diff --git a/arch/x86/include/asm/mktme.h
>b/arch/x86/include/asm/mktme.h
>> > index 44409b8bbaca..ebbee6a0c495 100644
>> > --- a/arch/x86/include/asm/mktme.h
>> > +++ b/arch/x86/include/asm/mktme.h
>> > @@ -6,6 +6,8 @@
>> >
>> > struct vm_area_struct;
>> >
>> > +void mktme_disable(void);
>> > +
>> > #ifdef CONFIG_X86_INTEL_MKTME
>> > extern phys_addr_t mktme_keyid_mask;
>> > extern int mktme_nr_keyids;
>> > diff --git a/arch/x86/kernel/cpu/intel.c
>b/arch/x86/kernel/cpu/intel.c
>> > index efc9e9fc47d4..75e3b2602b4a 100644
>> > --- a/arch/x86/kernel/cpu/intel.c
>> > +++ b/arch/x86/kernel/cpu/intel.c
>> > @@ -591,10 +591,7 @@ static void detect_tme(struct cpuinfo_x86 *c)
>> > * Maybe needed if there's inconsistent configuation
>> > * between CPUs.
>> > */
>> > - physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
>> > - mktme_keyid_mask = 0;
>> > - mktme_keyid_shift = 0;
>> > - mktme_nr_keyids = 0;
>> > + mktme_disable();
>> > }
>> > #endif
>> >
>> > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c
>> > index 1194496633ce..bb6210dbcf0e 100644
>> > --- a/arch/x86/mm/mktme.c
>> > +++ b/arch/x86/mm/mktme.c
>> > @@ -13,6 +13,15 @@ static inline bool mktme_enabled(void)
>> > return static_branch_unlikely(&mktme_enabled_key);
>> > }
>> >
>> > +void mktme_disable(void)
>> > +{
>> > + physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
>> > + mktme_keyid_mask = 0;
>> > + mktme_keyid_shift = 0;
>> > + mktme_nr_keyids = 0;
>> > + static_branch_disable(&mktme_enabled_key);
>> > +}
>> > +
>> > int page_keyid(const struct page *page)
>> > {
>> > if (!mktme_enabled())
>> > --
>> > 2.18.0
>> >
>>
