| Message ID | 158923997443.20128.16545619590919566266.stgit@naples-babu.amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arch/x86: Enable MPK feature on AMD | expand |
On 5/11/20 4:32 PM, Babu Moger wrote: > AMD's next generation of EPYC processors support the MPK (Memory > Protection Keys) feature. > > So, rename X86_INTEL_MEMORY_PROTECTION_KEYS to X86_MEMORY_PROTECTION_KEYS. > > No functional changes. > > AMD documentation for MPK feature is available at "AMD64 Architecture > Programmer’s Manual Volume 2: System Programming, Pub. 24593 Rev. 3.34, > Section 5.6.6 Memory Protection Keys (MPK) Bit". Documentation can be > obtained at the link below. I was hoping to see at least *some* justification in this changelog. Do you think having "INTEL_" will confuse users? Is there some technical merit to this change? The naming churn is an obviously bad, not technically necessary change. > +config X86_MEMORY_PROTECTION_KEYS > + # Note: This is an intermediate change to avoid config prompt to > + # the users. Eventually, the option X86_INTEL_MEMORY_PROTECTION_KEYS > + # should be changed to X86_MEMORY_PROTECTION_KEYS permanently after > + # few kernel revisions. > + def_bool X86_INTEL_MEMORY_PROTECTION_KEYS "after a few kernel revisions" is code for "never". :) Could we put an explicit date on this, please? One year seems roughly right. Or, maybe "after the v5.10" release, so that this will approach will make into at least one LTS kernel. Maybe: # Set the "INTEL_"-free option whenever the "INTEL_" one is set. # The "INTEL_" one should be removed and replaced by this option after # 5.10. This avoids exposing most 'oldconfig' users to this churn.
On 5/11/20 6:44 PM, Dave Hansen wrote: > On 5/11/20 4:32 PM, Babu Moger wrote: >> AMD's next generation of EPYC processors support the MPK (Memory >> Protection Keys) feature. >> >> So, rename X86_INTEL_MEMORY_PROTECTION_KEYS to X86_MEMORY_PROTECTION_KEYS. >> >> No functional changes. >> >> AMD documentation for MPK feature is available at "AMD64 Architecture >> Programmer’s Manual Volume 2: System Programming, Pub. 24593 Rev. 3.34, >> Section 5.6.6 Memory Protection Keys (MPK) Bit". Documentation can be >> obtained at the link below. I will remove this text. This is not too relevant here. > > I was hoping to see at least *some* justification in this changelog. Do > you think having "INTEL_" will confuse users? Is there some technical > merit to this change? > > The naming churn is an obviously bad, not technically necessary change. Yes. Technically not necessary. But can cause some confusion on non-intel platforms. > >> +config X86_MEMORY_PROTECTION_KEYS >> + # Note: This is an intermediate change to avoid config prompt to >> + # the users. Eventually, the option X86_INTEL_MEMORY_PROTECTION_KEYS >> + # should be changed to X86_MEMORY_PROTECTION_KEYS permanently after >> + # few kernel revisions. >> + def_bool X86_INTEL_MEMORY_PROTECTION_KEYS > > "after a few kernel revisions" is code for "never". :) > > Could we put an explicit date on this, please? One year seems roughly > right. Or, maybe "after the v5.10" release, so that this will approach > will make into at least one LTS kernel. > > Maybe: > > # Set the "INTEL_"-free option whenever the "INTEL_" one is set. > # The "INTEL_" one should be removed and replaced by this option after > # 5.10. This avoids exposing most 'oldconfig' users to this churn. > Yes, this should work.
On 5/12/20 7:57 AM, Babu Moger wrote: >> I was hoping to see at least *some* justification in this changelog. Do >> you think having "INTEL_" will confuse users? Is there some technical >> merit to this change? >> >> The naming churn is an obviously bad, not technically necessary change. > Yes. Technically not necessary. But can cause some confusion on non-intel > platforms. Seriously, guys, this is buried deep in kernel code. Who is this confusing? To me, this is like anything else we rename in the kernel. It causes churn, which makes patches harder to backport for instance. That's why we don't rename things willy-nilly when we just don't like the names. The naming has to cause some practical, real-world problem that we *FIX* with the rename. I'm just asking for a concrete, practical problem statement in the changelog. If there isn't one, then please don't do the rename. The Kconfig magic is still fine since it fixes a practical problem for end users.
On 5/12/20 10:19 AM, Dave Hansen wrote: > On 5/12/20 7:57 AM, Babu Moger wrote: >>> I was hoping to see at least *some* justification in this changelog. Do >>> you think having "INTEL_" will confuse users? Is there some technical >>> merit to this change? >>> >>> The naming churn is an obviously bad, not technically necessary change. >> Yes. Technically not necessary. But can cause some confusion on non-intel >> platforms. > > Seriously, guys, this is buried deep in kernel code. Who is this confusing? > > To me, this is like anything else we rename in the kernel. It causes > churn, which makes patches harder to backport for instance. That's why > we don't rename things willy-nilly when we just don't like the names. > > The naming has to cause some practical, real-world problem that we *FIX* > with the rename. > > I'm just asking for a concrete, practical problem statement in the > changelog. If there isn't one, then please don't do the rename. The > Kconfig magic is still fine since it fixes a practical problem for end > users. > Alright. Alright. I will just keep Kconfig magic and update the documentation(protection-keys.rst). Thanks
diff --git a/Documentation/core-api/protection-keys.rst b/Documentation/core-api/protection-keys.rst index 49d9833af871..d25e89e53c59 100644 --- a/Documentation/core-api/protection-keys.rst +++ b/Documentation/core-api/protection-keys.rst @@ -6,7 +6,8 @@ Memory Protection Keys Memory Protection Keys for Userspace (PKU aka PKEYs) is a feature which is found on Intel's Skylake "Scalable Processor" Server CPUs. -It will be avalable in future non-server parts. +It will be available in future non-server parts. Also, AMD64 +Architecture Programmer’s Manual defines PKU feature in AMD processors. For anyone wishing to test or use this feature, it is available in Amazon's EC2 C5 instances and is known to work there using an Ubuntu diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1197b5596d5a..b6f1686526eb 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1887,10 +1887,10 @@ config X86_UMIP results are dummy. config X86_INTEL_MEMORY_PROTECTION_KEYS - prompt "Intel Memory Protection Keys" + prompt "Memory Protection Keys" def_bool y # Note: only available in 64-bit mode - depends on CPU_SUP_INTEL && X86_64 + depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) select ARCH_USES_HIGH_VMA_FLAGS select ARCH_HAS_PKEYS ---help--- @@ -1902,6 +1902,13 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS If unsure, say y. +config X86_MEMORY_PROTECTION_KEYS + # Note: This is an intermediate change to avoid config prompt to + # the users. Eventually, the option X86_INTEL_MEMORY_PROTECTION_KEYS + # should be changed to X86_MEMORY_PROTECTION_KEYS permanently after + # few kernel revisions. + def_bool X86_INTEL_MEMORY_PROTECTION_KEYS + choice prompt "TSX enable mode" depends on CPU_SUP_INTEL diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 4ea8584682f9..52dbdfed8043 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -36,13 +36,13 @@ # define DISABLE_PCID (1<<(X86_FEATURE_PCID & 31)) #endif /* CONFIG_X86_64 */ -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS # define DISABLE_PKU 0 # define DISABLE_OSPKE 0 #else # define DISABLE_PKU (1<<(X86_FEATURE_PKU & 31)) # define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE & 31)) -#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */ +#endif /* CONFIG_X86_MEMORY_PROTECTION_KEYS */ #ifdef CONFIG_X86_5LEVEL # define DISABLE_LA57 0 diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h index bdeae9291e5c..351d22152709 100644 --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -42,7 +42,7 @@ typedef struct { const struct vdso_image *vdso_image; /* vdso image in use */ atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */ -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS /* * One bit per protection key says whether userspace can * use it or not. protected by mmap_sem. diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 4e55370e48e8..33f4a7ccac5e 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -118,7 +118,7 @@ static inline int init_new_context(struct task_struct *tsk, mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id); atomic64_set(&mm->context.tlb_gen, 0); -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS if (cpu_feature_enabled(X86_FEATURE_OSPKE)) { /* pkey 0 is the default and allocated implicitly */ mm->context.pkey_allocation_map = 0x1; @@ -163,7 +163,7 @@ do { \ static inline void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm) { -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) return; diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 4d02e64af1b3..4265720d62c2 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1451,7 +1451,7 @@ static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd) #define PKRU_WD_BIT 0x2 #define PKRU_BITS_PER_PKEY 2 -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS extern u32 init_pkru_value; #else #define init_pkru_value 0 @@ -1475,7 +1475,7 @@ static inline bool __pkru_allows_write(u32 pkru, u16 pkey) static inline u16 pte_flags_pkey(unsigned long pte_flags) { -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS /* ifdef to avoid doing 59-bit shift on 32-bit values */ return (pte_flags & _PAGE_PKEY_MASK) >> _PAGE_BIT_PKEY_BIT0; #else diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index b6606fe6cfdf..c61a1ff71d53 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -56,7 +56,7 @@ #define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE) #define _PAGE_SPECIAL (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL) #define _PAGE_CPA_TEST (_AT(pteval_t, 1) << _PAGE_BIT_CPA_TEST) -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS #define _PAGE_PKEY_BIT0 (_AT(pteval_t, 1) << _PAGE_BIT_PKEY_BIT0) #define _PAGE_PKEY_BIT1 (_AT(pteval_t, 1) << _PAGE_BIT_PKEY_BIT1) #define _PAGE_PKEY_BIT2 (_AT(pteval_t, 1) << _PAGE_BIT_PKEY_BIT2) diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index 6d37b8fcfc77..70eaae7e8f04 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -73,7 +73,7 @@ static inline unsigned long native_read_cr4(void) void native_write_cr4(unsigned long val); -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS static inline u32 rdpkru(void) { u32 ecx = 0; diff --git a/arch/x86/include/uapi/asm/mman.h b/arch/x86/include/uapi/asm/mman.h index d4a8d0424bfb..d4da414a9de2 100644 --- a/arch/x86/include/uapi/asm/mman.h +++ b/arch/x86/include/uapi/asm/mman.h @@ -4,7 +4,7 @@ #define MAP_32BIT 0x40 /* only give out 32bit addresses */ -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS /* * Take the 4 protection key bits out of the vma->vm_flags * value and turn them in to the bits that we can put in diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index bed0cb83fe24..e5fb9955214c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -448,7 +448,7 @@ static __always_inline void setup_pku(struct cpuinfo_x86 *c) set_cpu_cap(c, X86_FEATURE_OSPKE); } -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS static __init int setup_disable_pku(char *arg) { /* diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 98f7c6fa2eaa..17ebf12ba8ff 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -45,7 +45,7 @@ obj-$(CONFIG_AMD_NUMA) += amdtopology.o obj-$(CONFIG_ACPI_NUMA) += srat.o obj-$(CONFIG_NUMA_EMU) += numa_emulation.o -obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) += pkeys.o +obj-$(CONFIG_X86_MEMORY_PROTECTION_KEYS) += pkeys.o obj-$(CONFIG_RANDOMIZE_MEMORY) += kaslr.o obj-$(CONFIG_PAGE_TABLE_ISOLATION) += pti.o diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index 8873ed1438a9..a77497e8d58c 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * Intel Memory Protection Keys management + * Memory Protection Keys management * Copyright (c) 2015, Intel Corporation. */ #include <linux/debugfs.h> /* debugfs_create_u32() */ diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh index a07668a5c36b..6e60e5362d3e 100755 --- a/scripts/headers_install.sh +++ b/scripts/headers_install.sh @@ -86,7 +86,7 @@ arch/sh/include/uapi/asm/sigcontext.h:CONFIG_CPU_SH5 arch/sh/include/uapi/asm/stat.h:CONFIG_CPU_SH5 arch/x86/include/uapi/asm/auxvec.h:CONFIG_IA32_EMULATION arch/x86/include/uapi/asm/auxvec.h:CONFIG_X86_64 -arch/x86/include/uapi/asm/mman.h:CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +arch/x86/include/uapi/asm/mman.h:CONFIG_X86_MEMORY_PROTECTION_KEYS include/uapi/asm-generic/fcntl.h:CONFIG_64BIT include/uapi/linux/atmdev.h:CONFIG_COMPAT include/uapi/linux/elfcore.h:CONFIG_BINFMT_ELF_FDPIC diff --git a/tools/arch/x86/include/asm/disabled-features.h b/tools/arch/x86/include/asm/disabled-features.h index 4ea8584682f9..52dbdfed8043 100644 --- a/tools/arch/x86/include/asm/disabled-features.h +++ b/tools/arch/x86/include/asm/disabled-features.h @@ -36,13 +36,13 @@ # define DISABLE_PCID (1<<(X86_FEATURE_PCID & 31)) #endif /* CONFIG_X86_64 */ -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_X86_MEMORY_PROTECTION_KEYS # define DISABLE_PKU 0 # define DISABLE_OSPKE 0 #else # define DISABLE_PKU (1<<(X86_FEATURE_PKU & 31)) # define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE & 31)) -#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */ +#endif /* CONFIG_X86_MEMORY_PROTECTION_KEYS */ #ifdef CONFIG_X86_5LEVEL # define DISABLE_LA57 0
AMD's next generation of EPYC processors support the MPK (Memory Protection Keys) feature. So, rename X86_INTEL_MEMORY_PROTECTION_KEYS to X86_MEMORY_PROTECTION_KEYS. No functional changes. AMD documentation for MPK feature is available at "AMD64 Architecture Programmer’s Manual Volume 2: System Programming, Pub. 24593 Rev. 3.34, Section 5.6.6 Memory Protection Keys (MPK) Bit". Documentation can be obtained at the link below. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Signed-off-by: Babu Moger <babu.moger@amd.com> --- Documentation/core-api/protection-keys.rst | 3 ++- arch/x86/Kconfig | 11 +++++++++-- arch/x86/include/asm/disabled-features.h | 4 ++-- arch/x86/include/asm/mmu.h | 2 +- arch/x86/include/asm/mmu_context.h | 4 ++-- arch/x86/include/asm/pgtable.h | 4 ++-- arch/x86/include/asm/pgtable_types.h | 2 +- arch/x86/include/asm/special_insns.h | 2 +- arch/x86/include/uapi/asm/mman.h | 2 +- arch/x86/kernel/cpu/common.c | 2 +- arch/x86/mm/Makefile | 2 +- arch/x86/mm/pkeys.c | 2 +- scripts/headers_install.sh | 2 +- tools/arch/x86/include/asm/disabled-features.h | 4 ++-- 14 files changed, 27 insertions(+), 19 deletions(-)