From: Dan Williams <dan.j.williams@intel.com> To: mingo@redhat.com Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>, peterz@infradead.org, dave.hansen@linux.intel.com, x86@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-efi@vger.kernel.org Subject: [PATCH v8 04/12] efi: Common enable/disable infrastructure for EFI soft reservation Date: Wed, 06 Nov 2019 17:43:11 -0800 [thread overview] Message-ID: <157309099101.1579826.9700865115710403132.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <157309097008.1579826.12818463304589384434.stgit@dwillia2-desk3.amr.corp.intel.com> UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the interpretation of the EFI Memory Types as "reserved for a specific purpose". The proposed Linux behavior for specific purpose memory is that it is reserved for direct-access (device-dax) by default and not available for any kernel usage, not even as an OOM fallback. Later, through udev scripts or another init mechanism, these device-dax claimed ranges can be reconfigured and hot-added to the available System-RAM with a unique node identifier. This device-dax management scheme implements "soft" in the "soft reserved" designation by allowing some or all of the reservation to be recovered as typical memory. This policy can be disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with efi=nosoftreserve. As for this patch, define the common helpers to determine if the EFI_MEMORY_SP attribute should be honored. The determination needs to be made early to prevent the kernel from being loaded into soft-reserved memory, or otherwise allowing early allocations to land there. Follow-on changes are needed per architecture to leverage these helpers in their respective mem-init paths. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- Documentation/admin-guide/kernel-parameters.txt | 9 ++++++++- drivers/firmware/efi/Kconfig | 21 +++++++++++++++++++++ drivers/firmware/efi/efi.c | 8 ++++++++ drivers/firmware/efi/libstub/efi-stub-helper.c | 19 +++++++++++++++++++ include/linux/efi.h | 14 ++++++++++++++ 5 files changed, 70 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a84a83f8881e..2359dc56d82c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1168,7 +1168,8 @@ Format: {"off" | "on" | "skip[mbr]"} efi= [EFI] - Format: { "old_map", "nochunk", "noruntime", "debug" } + Format: { "old_map", "nochunk", "noruntime", "debug", + "nosoftreserve" } old_map [X86-64]: switch to the old ioremap-based EFI runtime services mapping. 32-bit still uses this one by default. @@ -1177,6 +1178,12 @@ firmware implementations. noruntime : disable EFI runtime services support debug: enable misc debug output + nosoftreserve: The EFI_MEMORY_SP (Specific Purpose) + attribute may cause the kernel to reserve the + memory range for a memory mapping driver to + claim. Specify efi=nosoftreserve to disable this + reservation and treat the memory by its base type + (i.e. EFI_CONVENTIONAL_MEMORY / "System RAM"). efi_no_storage_paranoia [EFI; X86] Using this parameter you can use more than 50% of diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index b248870a9806..bcc378c19ebe 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -75,6 +75,27 @@ config EFI_MAX_FAKE_MEM Ranges can be set up to this value using comma-separated list. The default value is 8. +config EFI_SOFT_RESERVE + bool "Reserve EFI Specific Purpose Memory" + depends on EFI && EFI_STUB && ACPI_HMAT + default ACPI_HMAT + help + On systems that have mixed performance classes of memory EFI + may indicate specific purpose memory with an attribute (See + EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this + attribute may have unique performance characteristics compared + to the system's general purpose "System RAM" pool. On the + expectation that such memory has application specific usage, + and its base EFI memory type is "conventional" answer Y to + arrange for the kernel to reserve it as a "Soft Reserved" + resource, and set aside for direct-access (device-dax) by + default. The memory range can later be optionally assigned to + the page allocator by system administrator policy via the + device-dax kmem facility. Say N to have the kernel treat this + memory as "System RAM" by default. + + If unsure, say Y. + config EFI_PARAMS_FROM_FDT bool help diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index f8f8e273d809..e1cb915b45c6 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -81,6 +81,11 @@ bool efi_runtime_disabled(void) return disable_runtime; } +bool __pure __efi_soft_reserve_enabled(void) +{ + return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE); +} + static int __init parse_efi_cmdline(char *str) { if (!str) { @@ -94,6 +99,9 @@ static int __init parse_efi_cmdline(char *str) if (parse_option_str(str, "noruntime")) disable_runtime = true; + if (parse_option_str(str, "nosoftreserve")) + set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags); + return 0; } early_param("efi", parse_efi_cmdline); diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 35dbc2791c97..e02579907f2e 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -32,6 +32,7 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; static int __section(.data) __nokaslr; static int __section(.data) __quiet; static int __section(.data) __novamap; +static bool __section(.data) efi_nosoftreserve; int __pure nokaslr(void) { @@ -45,6 +46,10 @@ int __pure novamap(void) { return __novamap; } +bool __pure __efi_soft_reserve_enabled(void) +{ + return !efi_nosoftreserve; +} #define EFI_MMAP_NR_SLACK_SLOTS 8 @@ -211,6 +216,10 @@ efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg, if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; + if (efi_soft_reserve_enabled() && + (desc->attribute & EFI_MEMORY_SP)) + continue; + if (desc->num_pages < nr_pages) continue; @@ -305,6 +314,10 @@ efi_status_t efi_low_alloc_above(efi_system_table_t *sys_table_arg, if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; + if (efi_soft_reserve_enabled() && + (desc->attribute & EFI_MEMORY_SP)) + continue; + if (desc->num_pages < nr_pages) continue; @@ -484,6 +497,12 @@ efi_status_t efi_parse_options(char const *cmdline) __novamap = 1; } + if (IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) && + !strncmp(str, "nosoftreserve", 7)) { + str += strlen("nosoftreserve"); + efi_nosoftreserve = 1; + } + /* Group words together, delimited by "," */ while (*str && *str != ' ' && *str != ',') str++; diff --git a/include/linux/efi.h b/include/linux/efi.h index 44c85b559e15..88654910ce29 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1202,6 +1202,7 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_DBG 8 /* Print additional debug info at runtime */ #define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ #define EFI_MEM_ATTR 10 /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */ +#define EFI_MEM_NO_SOFT_RESERVE 11 /* Is the kernel configured to ignore soft reservations? */ #ifdef CONFIG_EFI /* @@ -1212,6 +1213,14 @@ static inline bool efi_enabled(int feature) return test_bit(feature, &efi.flags) != 0; } extern void efi_reboot(enum reboot_mode reboot_mode, const char *__unused); + +bool __pure __efi_soft_reserve_enabled(void); + +static inline bool __pure efi_soft_reserve_enabled(void) +{ + return IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) + && __efi_soft_reserve_enabled(); +} #else static inline bool efi_enabled(int feature) { @@ -1225,6 +1234,11 @@ efi_capsule_pending(int *reset_type) { return false; } + +static inline bool efi_soft_reserve_enabled(void) +{ + return false; +} #endif extern int efi_status_to_err(efi_status_t status); _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com> To: mingo@redhat.com Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>, peterz@infradead.org, vishal.l.verma@intel.com, dave.hansen@linux.intel.com, x86@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-efi@vger.kernel.org Subject: [PATCH v8 04/12] efi: Common enable/disable infrastructure for EFI soft reservation Date: Wed, 06 Nov 2019 17:43:11 -0800 [thread overview] Message-ID: <157309099101.1579826.9700865115710403132.stgit@dwillia2-desk3.amr.corp.intel.com> (raw) In-Reply-To: <157309097008.1579826.12818463304589384434.stgit@dwillia2-desk3.amr.corp.intel.com> UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the interpretation of the EFI Memory Types as "reserved for a specific purpose". The proposed Linux behavior for specific purpose memory is that it is reserved for direct-access (device-dax) by default and not available for any kernel usage, not even as an OOM fallback. Later, through udev scripts or another init mechanism, these device-dax claimed ranges can be reconfigured and hot-added to the available System-RAM with a unique node identifier. This device-dax management scheme implements "soft" in the "soft reserved" designation by allowing some or all of the reservation to be recovered as typical memory. This policy can be disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with efi=nosoftreserve. As for this patch, define the common helpers to determine if the EFI_MEMORY_SP attribute should be honored. The determination needs to be made early to prevent the kernel from being loaded into soft-reserved memory, or otherwise allowing early allocations to land there. Follow-on changes are needed per architecture to leverage these helpers in their respective mem-init paths. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- Documentation/admin-guide/kernel-parameters.txt | 9 ++++++++- drivers/firmware/efi/Kconfig | 21 +++++++++++++++++++++ drivers/firmware/efi/efi.c | 8 ++++++++ drivers/firmware/efi/libstub/efi-stub-helper.c | 19 +++++++++++++++++++ include/linux/efi.h | 14 ++++++++++++++ 5 files changed, 70 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a84a83f8881e..2359dc56d82c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1168,7 +1168,8 @@ Format: {"off" | "on" | "skip[mbr]"} efi= [EFI] - Format: { "old_map", "nochunk", "noruntime", "debug" } + Format: { "old_map", "nochunk", "noruntime", "debug", + "nosoftreserve" } old_map [X86-64]: switch to the old ioremap-based EFI runtime services mapping. 32-bit still uses this one by default. @@ -1177,6 +1178,12 @@ firmware implementations. noruntime : disable EFI runtime services support debug: enable misc debug output + nosoftreserve: The EFI_MEMORY_SP (Specific Purpose) + attribute may cause the kernel to reserve the + memory range for a memory mapping driver to + claim. Specify efi=nosoftreserve to disable this + reservation and treat the memory by its base type + (i.e. EFI_CONVENTIONAL_MEMORY / "System RAM"). efi_no_storage_paranoia [EFI; X86] Using this parameter you can use more than 50% of diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index b248870a9806..bcc378c19ebe 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -75,6 +75,27 @@ config EFI_MAX_FAKE_MEM Ranges can be set up to this value using comma-separated list. The default value is 8. +config EFI_SOFT_RESERVE + bool "Reserve EFI Specific Purpose Memory" + depends on EFI && EFI_STUB && ACPI_HMAT + default ACPI_HMAT + help + On systems that have mixed performance classes of memory EFI + may indicate specific purpose memory with an attribute (See + EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this + attribute may have unique performance characteristics compared + to the system's general purpose "System RAM" pool. On the + expectation that such memory has application specific usage, + and its base EFI memory type is "conventional" answer Y to + arrange for the kernel to reserve it as a "Soft Reserved" + resource, and set aside for direct-access (device-dax) by + default. The memory range can later be optionally assigned to + the page allocator by system administrator policy via the + device-dax kmem facility. Say N to have the kernel treat this + memory as "System RAM" by default. + + If unsure, say Y. + config EFI_PARAMS_FROM_FDT bool help diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index f8f8e273d809..e1cb915b45c6 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -81,6 +81,11 @@ bool efi_runtime_disabled(void) return disable_runtime; } +bool __pure __efi_soft_reserve_enabled(void) +{ + return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE); +} + static int __init parse_efi_cmdline(char *str) { if (!str) { @@ -94,6 +99,9 @@ static int __init parse_efi_cmdline(char *str) if (parse_option_str(str, "noruntime")) disable_runtime = true; + if (parse_option_str(str, "nosoftreserve")) + set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags); + return 0; } early_param("efi", parse_efi_cmdline); diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 35dbc2791c97..e02579907f2e 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -32,6 +32,7 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; static int __section(.data) __nokaslr; static int __section(.data) __quiet; static int __section(.data) __novamap; +static bool __section(.data) efi_nosoftreserve; int __pure nokaslr(void) { @@ -45,6 +46,10 @@ int __pure novamap(void) { return __novamap; } +bool __pure __efi_soft_reserve_enabled(void) +{ + return !efi_nosoftreserve; +} #define EFI_MMAP_NR_SLACK_SLOTS 8 @@ -211,6 +216,10 @@ efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg, if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; + if (efi_soft_reserve_enabled() && + (desc->attribute & EFI_MEMORY_SP)) + continue; + if (desc->num_pages < nr_pages) continue; @@ -305,6 +314,10 @@ efi_status_t efi_low_alloc_above(efi_system_table_t *sys_table_arg, if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; + if (efi_soft_reserve_enabled() && + (desc->attribute & EFI_MEMORY_SP)) + continue; + if (desc->num_pages < nr_pages) continue; @@ -484,6 +497,12 @@ efi_status_t efi_parse_options(char const *cmdline) __novamap = 1; } + if (IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) && + !strncmp(str, "nosoftreserve", 7)) { + str += strlen("nosoftreserve"); + efi_nosoftreserve = 1; + } + /* Group words together, delimited by "," */ while (*str && *str != ' ' && *str != ',') str++; diff --git a/include/linux/efi.h b/include/linux/efi.h index 44c85b559e15..88654910ce29 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1202,6 +1202,7 @@ extern int __init efi_setup_pcdp_console(char *); #define EFI_DBG 8 /* Print additional debug info at runtime */ #define EFI_NX_PE_DATA 9 /* Can runtime data regions be mapped non-executable? */ #define EFI_MEM_ATTR 10 /* Did firmware publish an EFI_MEMORY_ATTRIBUTES table? */ +#define EFI_MEM_NO_SOFT_RESERVE 11 /* Is the kernel configured to ignore soft reservations? */ #ifdef CONFIG_EFI /* @@ -1212,6 +1213,14 @@ static inline bool efi_enabled(int feature) return test_bit(feature, &efi.flags) != 0; } extern void efi_reboot(enum reboot_mode reboot_mode, const char *__unused); + +bool __pure __efi_soft_reserve_enabled(void); + +static inline bool __pure efi_soft_reserve_enabled(void) +{ + return IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) + && __efi_soft_reserve_enabled(); +} #else static inline bool efi_enabled(int feature) { @@ -1225,6 +1234,11 @@ efi_capsule_pending(int *reset_type) { return false; } + +static inline bool efi_soft_reserve_enabled(void) +{ + return false; +} #endif extern int efi_status_to_err(efi_status_t status);
next prev parent reply other threads:[~2019-11-07 1:57 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-07 1:42 [PATCH v8 00/12] EFI Specific Purpose Memory Support Dan Williams 2019-11-07 1:42 ` Dan Williams 2019-11-07 1:42 ` [PATCH v8 01/12] acpi/numa: Establish a new drivers/acpi/numa/ directory Dan Williams 2019-11-07 1:42 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 02/12] efi: Enumerate EFI_MEMORY_SP Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 03/12] x86/efi: Push EFI_MEMMAP check into leaf routines Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` Dan Williams [this message] 2019-11-07 1:43 ` [PATCH v8 04/12] efi: Common enable/disable infrastructure for EFI soft reservation Dan Williams 2019-11-07 1:43 ` [PATCH v8 05/12] x86/efi: EFI soft reservation to E820 enumeration Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 06/12] arm/efi: EFI soft reservation to memblock Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 07/12] x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 08/12] lib: Uplevel the pmem "region" ida to a global allocator Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 09/12] dax: Fix alloc_dax_region() compile warning Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 10/12] device-dax: Add a driver for "hmem" devices Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 11/12] acpi/numa/hmat: Register HMAT at device_initcall level Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 1:43 ` [PATCH v8 12/12] acpi/numa/hmat: Register "soft reserved" memory as an "hmem" device Dan Williams 2019-11-07 1:43 ` Dan Williams 2019-11-07 12:46 ` [PATCH v8 00/12] EFI Specific Purpose Memory Support Rafael J. Wysocki 2019-11-07 12:46 ` Rafael J. Wysocki 2019-11-07 13:48 ` Thomas Gleixner 2019-11-07 13:48 ` Thomas Gleixner 2019-11-07 14:12 ` Rafael J. Wysocki 2019-11-07 14:12 ` Rafael J. Wysocki
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