| Message ID | 20170724190757.11278-8-brijesh.singh@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jul 24, 2017 at 02:07:47PM -0500, Brijesh Singh wrote: > From: Tom Lendacky <thomas.lendacky@amd.com> > > The current code checks only for sme_active() when determining whether > to perform the encryption attribute change. Include sev_active() in this > check so that memory attribute changes can occur under SME and SEV. > > Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > --- > arch/x86/mm/pageattr.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c > index dfb7d65..b726b23 100644 > --- a/arch/x86/mm/pageattr.c > +++ b/arch/x86/mm/pageattr.c > @@ -1781,8 +1781,8 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > unsigned long start; > int ret; > > - /* Nothing to do if the SME is not active */ > - if (!sme_active()) > + /* Nothing to do if SME and SEV are not active */ > + if (!sme_active() && !sev_active()) This is the second place which does if (!SME && !SEV) I wonder if, instead of sprinking those, we should have a if (mem_enc_active()) or so which unifies all those memory encryption logic tests and makes the code more straightforward for readers who don't have to pay attention to SME vs SEV ... Just a thought.
From: Borislav Petkov > Sent: 27 July 2017 15:59 > On Mon, Jul 24, 2017 at 02:07:47PM -0500, Brijesh Singh wrote: > > From: Tom Lendacky <thomas.lendacky@amd.com> > > > > The current code checks only for sme_active() when determining whether > > to perform the encryption attribute change. Include sev_active() in this > > check so that memory attribute changes can occur under SME and SEV. > > > > Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> > > Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> > > --- > > arch/x86/mm/pageattr.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c > > index dfb7d65..b726b23 100644 > > --- a/arch/x86/mm/pageattr.c > > +++ b/arch/x86/mm/pageattr.c > > @@ -1781,8 +1781,8 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) > > unsigned long start; > > int ret; > > > > - /* Nothing to do if the SME is not active */ > > - if (!sme_active()) > > + /* Nothing to do if SME and SEV are not active */ > > + if (!sme_active() && !sev_active()) > > This is the second place which does > > if (!SME && !SEV) > > I wonder if, instead of sprinking those, we should have a > > if (mem_enc_active()) > > or so which unifies all those memory encryption logic tests and makes > the code more straightforward for readers who don't have to pay > attention to SME vs SEV ... If any of the code paths are 'hot' it would make sense to be checking a single memory location. David
On 7/27/2017 9:58 AM, Borislav Petkov wrote: > On Mon, Jul 24, 2017 at 02:07:47PM -0500, Brijesh Singh wrote: >> From: Tom Lendacky <thomas.lendacky@amd.com> >> >> The current code checks only for sme_active() when determining whether >> to perform the encryption attribute change. Include sev_active() in this >> check so that memory attribute changes can occur under SME and SEV. >> >> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> --- >> arch/x86/mm/pageattr.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c >> index dfb7d65..b726b23 100644 >> --- a/arch/x86/mm/pageattr.c >> +++ b/arch/x86/mm/pageattr.c >> @@ -1781,8 +1781,8 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) >> unsigned long start; >> int ret; >> >> - /* Nothing to do if the SME is not active */ >> - if (!sme_active()) >> + /* Nothing to do if SME and SEV are not active */ >> + if (!sme_active() && !sev_active()) > > This is the second place which does > > if (!SME && !SEV) > > I wonder if, instead of sprinking those, we should have a > > if (mem_enc_active()) > > or so which unifies all those memory encryption logic tests and makes > the code more straightforward for readers who don't have to pay > attention to SME vs SEV ... Yup, that will make things look cleaner and easier to understand. Thanks, Tom > > Just a thought. >
On 7/28/2017 3:47 AM, David Laight wrote: > From: Borislav Petkov >> Sent: 27 July 2017 15:59 >> On Mon, Jul 24, 2017 at 02:07:47PM -0500, Brijesh Singh wrote: >>> From: Tom Lendacky <thomas.lendacky@amd.com> >>> >>> The current code checks only for sme_active() when determining whether >>> to perform the encryption attribute change. Include sev_active() in this >>> check so that memory attribute changes can occur under SME and SEV. >>> >>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> >>> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >>> --- >>> arch/x86/mm/pageattr.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c >>> index dfb7d65..b726b23 100644 >>> --- a/arch/x86/mm/pageattr.c >>> +++ b/arch/x86/mm/pageattr.c >>> @@ -1781,8 +1781,8 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) >>> unsigned long start; >>> int ret; >>> >>> - /* Nothing to do if the SME is not active */ >>> - if (!sme_active()) >>> + /* Nothing to do if SME and SEV are not active */ >>> + if (!sme_active() && !sev_active()) >> >> This is the second place which does >> >> if (!SME && !SEV) >> >> I wonder if, instead of sprinking those, we should have a >> >> if (mem_enc_active()) >> >> or so which unifies all those memory encryption logic tests and makes >> the code more straightforward for readers who don't have to pay >> attention to SME vs SEV ... > > If any of the code paths are 'hot' it would make sense to be checking > a single memory location. The function would check a single variable/memory location and making it an inline function would accomplish that. Thanks, Tom > > David >
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index dfb7d65..b726b23 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -1781,8 +1781,8 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) unsigned long start; int ret; - /* Nothing to do if the SME is not active */ - if (!sme_active()) + /* Nothing to do if SME and SEV are not active */ + if (!sme_active() && !sev_active()) return 0; /* Should not be working on unaligned addresses */