diff --git a/docs/misc/cache-coloring.rst b/docs/misc/cache-coloring.rst index 371f21a0e7..12972dbb2c 100644 --- a/docs/misc/cache-coloring.rst +++ b/docs/misc/cache-coloring.rst @@ -113,6 +113,20 @@ Auto-probing of LLC specs LLC size and number of ways are probed automatically by default. +In the Arm implementation, this is done by inspecting the CLIDR_EL1 register. +This means that other system caches that aren't visible there are ignored. + LLC specs can be manually set via the above command line parameters. This bypasses any auto-probing and it's used to overcome failing situations, such as flawed probing logic, or for debugging/testing purposes. + +Known issues and limitations +**************************** + +"xen,static-mem" isn't supported when coloring is enabled +######################################################### + +In the domain configuration, "xen,static-mem" allows memory to be statically +allocated to the domain. This isn't possible when LLC coloring is enabled, +because that memory can't be guaranteed to use only colors assigned to the +domain. diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig index 604aba4996..c5e7b74733 100644 --- a/xen/arch/arm/Kconfig +++ b/xen/arch/arm/Kconfig @@ -8,6 +8,7 @@ config ARM_64 depends on !ARM_32 select 64BIT select HAS_FAST_MULTIPLY + select HAS_LLC_COLORING if !NUMA config ARM def_bool y diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index e4ad1ce851..ccbfc61f88 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -35,6 +35,7 @@ obj-$(CONFIG_IOREQ_SERVER) += ioreq.o obj-y += irq.o obj-y += kernel.init.o obj-$(CONFIG_LIVEPATCH) += livepatch.o +obj-$(CONFIG_LLC_COLORING) += llc-coloring.o obj-$(CONFIG_MEM_ACCESS) += mem_access.o obj-y += mm.o obj-y += monitor.o diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c index f328a044e9..d93a85434e 100644 --- a/xen/arch/arm/dom0less-build.c +++ b/xen/arch/arm/dom0less-build.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include #include @@ -890,7 +891,12 @@ void __init create_domUs(void) panic("No more domain IDs available\n"); if ( dt_find_property(node, "xen,static-mem", NULL) ) + { + if ( llc_coloring_enabled ) + panic("LLC coloring and static memory are incompatible\n"); + flags |= CDF_staticmem; + } if ( dt_property_read_bool(node, "direct-map") ) { diff --git a/xen/arch/arm/include/asm/processor.h b/xen/arch/arm/include/asm/processor.h index 8e02410465..60b587db69 100644 --- a/xen/arch/arm/include/asm/processor.h +++ b/xen/arch/arm/include/asm/processor.h @@ -18,6 +18,21 @@ #define CTR_IDC_SHIFT 28 #define CTR_DIC_SHIFT 29 +/* CCSIDR Current Cache Size ID Register */ +#define CCSIDR_LINESIZE_MASK _AC(0x7, UL) +#define CCSIDR_NUMSETS_SHIFT 13 +#define CCSIDR_NUMSETS_MASK _AC(0x3fff, UL) +#define CCSIDR_NUMSETS_SHIFT_FEAT_CCIDX 32 +#define CCSIDR_NUMSETS_MASK_FEAT_CCIDX _AC(0xffffff, UL) + +/* CSSELR Cache Size Selection Register */ +#define CSSELR_LEVEL_SHIFT 1 + +/* CLIDR Cache Level ID Register */ +#define CLIDR_CTYPEn_SHIFT(n) (3 * ((n) - 1)) +#define CLIDR_CTYPEn_MASK _AC(0x7, UL) +#define CLIDR_CTYPEn_LEVELS 7 + #define ICACHE_POLICY_VPIPT 0 #define ICACHE_POLICY_AIVIVT 1 #define ICACHE_POLICY_VIPT 2 diff --git a/xen/arch/arm/llc-coloring.c b/xen/arch/arm/llc-coloring.c new file mode 100644 index 0000000000..1c7b92bc45 --- /dev/null +++ b/xen/arch/arm/llc-coloring.c @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Last Level Cache (LLC) coloring support for ARM + * + * Copyright (C) 2024, Advanced Micro Devices, Inc. + * Copyright (C) 2024, Minerva Systems SRL + */ +#include +#include + +#include +#include +#include + +/* Return the LLC way size by probing the hardware */ +unsigned int __init get_llc_way_size(void) +{ + register_t ccsidr_el1; + register_t clidr_el1 = READ_SYSREG(CLIDR_EL1); + register_t csselr_el1 = READ_SYSREG(CSSELR_EL1); + register_t id_aa64mmfr2_el1 = READ_SYSREG(ID_AA64MMFR2_EL1); + uint32_t ccsidr_numsets_shift = CCSIDR_NUMSETS_SHIFT; + uint32_t ccsidr_numsets_mask = CCSIDR_NUMSETS_MASK; + unsigned int n, line_size, num_sets; + + for ( n = CLIDR_CTYPEn_LEVELS; n != 0; n-- ) + { + uint8_t ctype_n = (clidr_el1 >> CLIDR_CTYPEn_SHIFT(n)) & + CLIDR_CTYPEn_MASK; + + /* Unified cache (see Arm ARM DDI 0487J.a D19.2.27) */ + if ( ctype_n == 0b100 ) + break; + } + + if ( n == 0 ) + return 0; + + WRITE_SYSREG((n - 1) << CSSELR_LEVEL_SHIFT, CSSELR_EL1); + isb(); + + ccsidr_el1 = READ_SYSREG(CCSIDR_EL1); + + /* Arm ARM: (Log2(Number of bytes in cache line)) - 4 */ + line_size = 1U << ((ccsidr_el1 & CCSIDR_LINESIZE_MASK) + 4); + + /* If FEAT_CCIDX is enabled, CCSIDR_EL1 has a different bit layout */ + if ( (id_aa64mmfr2_el1 >> ID_AA64MMFR2_CCIDX_SHIFT) & 0x7 ) + { + ccsidr_numsets_shift = CCSIDR_NUMSETS_SHIFT_FEAT_CCIDX; + ccsidr_numsets_mask = CCSIDR_NUMSETS_MASK_FEAT_CCIDX; + } + + /* Arm ARM: (Number of sets in cache) - 1 */ + num_sets = ((ccsidr_el1 >> ccsidr_numsets_shift) & ccsidr_numsets_mask) + 1; + + printk(XENLOG_INFO "LLC found: L%u (line size: %u bytes, sets num: %u)\n", + n, line_size, num_sets); + + /* Restore value in CSSELR_EL1 */ + WRITE_SYSREG(csselr_el1, CSSELR_EL1); + isb(); + + return line_size * num_sets; +} + +void __init arch_llc_coloring_init(void) +{ +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c index 545702d8a3..5f1993ffed 100644 --- a/xen/arch/arm/setup.c +++ b/xen/arch/arm/setup.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -334,6 +335,8 @@ void asmlinkage __init start_xen(unsigned long fdt_paddr) printk("Command line: %s\n", cmdline); cmdline_parse(cmdline); + llc_coloring_init(); + setup_mm(); vm_init(); diff --git a/xen/common/llc-coloring.c b/xen/common/llc-coloring.c index 335a907296..b034c0169c 100644 --- a/xen/common/llc-coloring.c +++ b/xen/common/llc-coloring.c @@ -8,6 +8,8 @@ #include #include #include +#include +#include #define NR_LLC_COLORS (1U << CONFIG_LLC_COLORS_ORDER) @@ -19,7 +21,7 @@ static int8_t __initdata opt_llc_coloring = -1; boolean_param("llc-coloring", opt_llc_coloring); -static bool __ro_after_init llc_coloring_enabled; +bool __ro_after_init llc_coloring_enabled; static unsigned int __initdata llc_size; size_param("llc-size", llc_size); diff --git a/xen/include/xen/llc-coloring.h b/xen/include/xen/llc-coloring.h index 0acd8d0ad6..a3ebb17186 100644 --- a/xen/include/xen/llc-coloring.h +++ b/xen/include/xen/llc-coloring.h @@ -8,13 +8,19 @@ #ifndef __XEN_LLC_COLORING_H__ #define __XEN_LLC_COLORING_H__ +#include + struct domain; #ifdef CONFIG_LLC_COLORING +extern bool llc_coloring_enabled; + void llc_coloring_init(void); void dump_llc_coloring_info(void); void domain_dump_llc_colors(const struct domain *d); #else +#define llc_coloring_enabled false + static inline void llc_coloring_init(void) {} static inline void dump_llc_coloring_info(void) {} static inline void domain_dump_llc_colors(const struct domain *d) {}