| Message ID | 20200821010837.4079-3-shawn@anastas.io (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Reintroduce PROT_SAO | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (d4ecce4dcc8f8820286cf4e0859850c555e89854) |
| snowpatch_ozlabs/build-ppc64le | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-ppc64be | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-ppc64e | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/build-pmac32 | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 33 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
Excerpts from Shawn Anastasio's message of August 21, 2020 11:08 am: > Since migration of guests using SAO to ISA 3.1 hosts may cause issues, > disable PROT_SAO in LPARs by default and introduce a new Kconfig option > PPC_PROT_SAO_LPAR to allow users to enable it if desired. I think this should be okay. Could you also update the selftest to skip if we have PPC_FEATURE2_ARCH_3_1 set? Thanks, Nick Acked-by: Nicholas Piggin <npiggin@gmail.com> > > Signed-off-by: Shawn Anastasio <shawn@anastas.io> > --- > arch/powerpc/Kconfig | 12 ++++++++++++ > arch/powerpc/include/asm/mman.h | 9 +++++++-- > 2 files changed, 19 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 1f48bbfb3ce9..65bed1fdeaad 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -860,6 +860,18 @@ config PPC_SUBPAGE_PROT > > If unsure, say N here. > > +config PPC_PROT_SAO_LPAR > + bool "Support PROT_SAO mappings in LPARs" > + depends on PPC_BOOK3S_64 > + help > + This option adds support for PROT_SAO mappings from userspace > + inside LPARs on supported CPUs. > + > + This may cause issues when performing guest migration from > + a CPU that supports SAO to one that does not. > + > + If unsure, say N here. > + > config PPC_COPRO_BASE > bool > > diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h > index 4ba303ea27f5..7cb6d18f5cd6 100644 > --- a/arch/powerpc/include/asm/mman.h > +++ b/arch/powerpc/include/asm/mman.h > @@ -40,8 +40,13 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) > { > if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO)) > return false; > - if ((prot & PROT_SAO) && !cpu_has_feature(CPU_FTR_SAO)) > - return false; > + if (prot & PROT_SAO) { > + if (!cpu_has_feature(CPU_FTR_SAO)) > + return false; > + if (firmware_has_feature(FW_FEATURE_LPAR) && > + !IS_ENABLED(CONFIG_PPC_PROT_SAO_LPAR)) > + return false; > + } > return true; > } > #define arch_validate_prot arch_validate_prot > -- > 2.28.0 > >
On 8/21/20 5:37 AM, Nicholas Piggin wrote:> I think this should be okay. Could you also update the selftest to skip > if we have PPC_FEATURE2_ARCH_3_1 set? Sure. I'll send out a v2 shortly with another patch for this. > Thanks, > Nick Thanks, Shawn
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 1f48bbfb3ce9..65bed1fdeaad 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -860,6 +860,18 @@ config PPC_SUBPAGE_PROT If unsure, say N here. +config PPC_PROT_SAO_LPAR + bool "Support PROT_SAO mappings in LPARs" + depends on PPC_BOOK3S_64 + help + This option adds support for PROT_SAO mappings from userspace + inside LPARs on supported CPUs. + + This may cause issues when performing guest migration from + a CPU that supports SAO to one that does not. + + If unsure, say N here. + config PPC_COPRO_BASE bool diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h index 4ba303ea27f5..7cb6d18f5cd6 100644 --- a/arch/powerpc/include/asm/mman.h +++ b/arch/powerpc/include/asm/mman.h @@ -40,8 +40,13 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) { if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO)) return false; - if ((prot & PROT_SAO) && !cpu_has_feature(CPU_FTR_SAO)) - return false; + if (prot & PROT_SAO) { + if (!cpu_has_feature(CPU_FTR_SAO)) + return false; + if (firmware_has_feature(FW_FEATURE_LPAR) && + !IS_ENABLED(CONFIG_PPC_PROT_SAO_LPAR)) + return false; + } return true; } #define arch_validate_prot arch_validate_prot
Since migration of guests using SAO to ISA 3.1 hosts may cause issues, disable PROT_SAO in LPARs by default and introduce a new Kconfig option PPC_PROT_SAO_LPAR to allow users to enable it if desired. Signed-off-by: Shawn Anastasio <shawn@anastas.io> --- arch/powerpc/Kconfig | 12 ++++++++++++ arch/powerpc/include/asm/mman.h | 9 +++++++-- 2 files changed, 19 insertions(+), 2 deletions(-)