diff options
| -rw-r--r-- | Documentation/virt/kvm/s390/s390-diag.rst | 35 | ||||
| -rw-r--r-- | arch/s390/boot/physmem_info.c | 47 | ||||
| -rw-r--r-- | arch/s390/boot/startup.c | 7 | ||||
| -rw-r--r-- | arch/s390/include/asm/physmem_info.h | 3 | ||||
| -rw-r--r-- | arch/s390/include/asm/sparsemem.h | 10 | ||||
| -rw-r--r-- | drivers/virtio/Kconfig | 12 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 2 |
7 files changed, 98 insertions, 18 deletions
diff --git a/Documentation/virt/kvm/s390/s390-diag.rst b/Documentation/virt/kvm/s390/s390-diag.rst index ca85f030eb0b..3e4f9e3bef81 100644 --- a/Documentation/virt/kvm/s390/s390-diag.rst +++ b/Documentation/virt/kvm/s390/s390-diag.rst @@ -35,20 +35,24 @@ DIAGNOSE function codes not specific to KVM, please refer to the documentation for the s390 hypervisors defining them. -DIAGNOSE function code 'X'500' - KVM virtio functions ------------------------------------------------------ +DIAGNOSE function code 'X'500' - KVM functions +---------------------------------------------- -If the function code specifies 0x500, various virtio-related functions -are performed. +If the function code specifies 0x500, various KVM-specific functions +are performed, including virtio functions. -General register 1 contains the virtio subfunction code. Supported -virtio subfunctions depend on KVM's userspace. Generally, userspace -provides either s390-virtio (subcodes 0-2) or virtio-ccw (subcode 3). +General register 1 contains the subfunction code. Supported subfunctions +depend on KVM's userspace. Regarding virtio subfunctions, generally +userspace provides either s390-virtio (subcodes 0-2) or virtio-ccw +(subcode 3). Upon completion of the DIAGNOSE instruction, general register 2 contains the function's return code, which is either a return code or a subcode specific value. +If the specified subfunction is not supported, a SPECIFICATION exception +will be triggered. + Subcode 0 - s390-virtio notification and early console printk Handled by userspace. @@ -76,6 +80,23 @@ Subcode 3 - virtio-ccw notification See also the virtio standard for a discussion of this hypercall. +Subcode 4 - storage-limit + Handled by userspace. + + After completion of the DIAGNOSE call, general register 2 will + contain the storage limit: the maximum physical address that might be + used for storage throughout the lifetime of the VM. + + The storage limit does not indicate currently usable storage, it may + include holes, standby storage and areas reserved for other means, such + as memory hotplug or virtio-mem devices. Other interfaces for detecting + actually usable storage, such as SCLP, must be used in conjunction with + this subfunction. + + Note that the storage limit can be larger, but never smaller than the + maximum storage address indicated by SCLP via the "maximum storage + increment" and the "increment size". + DIAGNOSE function code 'X'501 - KVM breakpoint ---------------------------------------------- diff --git a/arch/s390/boot/physmem_info.c b/arch/s390/boot/physmem_info.c index 1d131a81cb8b..f3ea5dbff10b 100644 --- a/arch/s390/boot/physmem_info.c +++ b/arch/s390/boot/physmem_info.c @@ -109,6 +109,42 @@ static int diag260(void) return 0; } +#define DIAG500_SC_STOR_LIMIT 4 + +static int diag500_storage_limit(unsigned long *max_physmem_end) +{ + unsigned long storage_limit; + unsigned long reg1, reg2; + psw_t old; + + asm volatile( + " mvc 0(16,%[psw_old]),0(%[psw_pgm])\n" + " epsw %[reg1],%[reg2]\n" + " st %[reg1],0(%[psw_pgm])\n" + " st %[reg2],4(%[psw_pgm])\n" + " larl %[reg1],1f\n" + " stg %[reg1],8(%[psw_pgm])\n" + " lghi 1,%[subcode]\n" + " lghi 2,0\n" + " diag 2,4,0x500\n" + "1: mvc 0(16,%[psw_pgm]),0(%[psw_old])\n" + " lgr %[slimit],2\n" + : [reg1] "=&d" (reg1), + [reg2] "=&a" (reg2), + [slimit] "=d" (storage_limit), + "=Q" (get_lowcore()->program_new_psw), + "=Q" (old) + : [psw_old] "a" (&old), + [psw_pgm] "a" (&get_lowcore()->program_new_psw), + [subcode] "i" (DIAG500_SC_STOR_LIMIT) + : "memory", "1", "2"); + if (!storage_limit) + return -EINVAL; + /* Convert inclusive end to exclusive end */ + *max_physmem_end = storage_limit + 1; + return 0; +} + static int tprot(unsigned long addr) { unsigned long reg1, reg2; @@ -157,7 +193,9 @@ unsigned long detect_max_physmem_end(void) { unsigned long max_physmem_end = 0; - if (!sclp_early_get_memsize(&max_physmem_end)) { + if (!diag500_storage_limit(&max_physmem_end)) { + physmem_info.info_source = MEM_DETECT_DIAG500_STOR_LIMIT; + } else if (!sclp_early_get_memsize(&max_physmem_end)) { physmem_info.info_source = MEM_DETECT_SCLP_READ_INFO; } else { max_physmem_end = search_mem_end(); @@ -170,6 +208,13 @@ void detect_physmem_online_ranges(unsigned long max_physmem_end) { if (!sclp_early_read_storage_info()) { physmem_info.info_source = MEM_DETECT_SCLP_STOR_INFO; + } else if (physmem_info.info_source == MEM_DETECT_DIAG500_STOR_LIMIT) { + unsigned long online_end; + + if (!sclp_early_get_memsize(&online_end)) { + physmem_info.info_source = MEM_DETECT_SCLP_READ_INFO; + add_physmem_online_range(0, online_end); + } } else if (!diag260()) { physmem_info.info_source = MEM_DETECT_DIAG260; } else if (max_physmem_end) { diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c index bf145965baf2..abe6e6c0ab98 100644 --- a/arch/s390/boot/startup.c +++ b/arch/s390/boot/startup.c @@ -182,12 +182,15 @@ static void kaslr_adjust_got(unsigned long offset) * Merge information from several sources into a single ident_map_size value. * "ident_map_size" represents the upper limit of physical memory we may ever * reach. It might not be all online memory, but also include standby (offline) - * memory. "ident_map_size" could be lower then actual standby or even online + * memory or memory areas reserved for other means (e.g., memory devices such as + * virtio-mem). + * + * "ident_map_size" could be lower then actual standby/reserved or even online * memory present, due to limiting factors. We should never go above this limit. * It is the size of our identity mapping. * * Consider the following factors: - * 1. max_physmem_end - end of physical memory online or standby. + * 1. max_physmem_end - end of physical memory online, standby or reserved. * Always >= end of the last online memory range (get_physmem_online_end()). * 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the * kernel is able to support. diff --git a/arch/s390/include/asm/physmem_info.h b/arch/s390/include/asm/physmem_info.h index f45cfc8bc233..51b68a43e195 100644 --- a/arch/s390/include/asm/physmem_info.h +++ b/arch/s390/include/asm/physmem_info.h @@ -9,6 +9,7 @@ enum physmem_info_source { MEM_DETECT_NONE = 0, MEM_DETECT_SCLP_STOR_INFO, MEM_DETECT_DIAG260, + MEM_DETECT_DIAG500_STOR_LIMIT, MEM_DETECT_SCLP_READ_INFO, MEM_DETECT_BIN_SEARCH }; @@ -107,6 +108,8 @@ static inline const char *get_physmem_info_source(void) return "sclp storage info"; case MEM_DETECT_DIAG260: return "diag260"; + case MEM_DETECT_DIAG500_STOR_LIMIT: + return "diag500 storage limit"; case MEM_DETECT_SCLP_READ_INFO: return "sclp read info"; case MEM_DETECT_BIN_SEARCH: diff --git a/arch/s390/include/asm/sparsemem.h b/arch/s390/include/asm/sparsemem.h index c549893602ea..6377b7ea8a40 100644 --- a/arch/s390/include/asm/sparsemem.h +++ b/arch/s390/include/asm/sparsemem.h @@ -2,7 +2,15 @@ #ifndef _ASM_S390_SPARSEMEM_H #define _ASM_S390_SPARSEMEM_H -#define SECTION_SIZE_BITS 28 +#define SECTION_SIZE_BITS 27 #define MAX_PHYSMEM_BITS CONFIG_MAX_PHYSMEM_BITS +#ifdef CONFIG_NUMA +static inline int memory_add_physaddr_to_nid(u64 addr) +{ + return 0; +} +#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid +#endif /* CONFIG_NUMA */ + #endif /* _ASM_S390_SPARSEMEM_H */ diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index 42a48ac763ee..2eb747311bfd 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -122,7 +122,7 @@ config VIRTIO_BALLOON config VIRTIO_MEM tristate "Virtio mem driver" - depends on X86_64 || ARM64 || RISCV + depends on X86_64 || ARM64 || RISCV || S390 depends on VIRTIO depends on MEMORY_HOTPLUG depends on MEMORY_HOTREMOVE @@ -132,11 +132,11 @@ config VIRTIO_MEM This driver provides access to virtio-mem paravirtualized memory devices, allowing to hotplug and hotunplug memory. - This driver currently only supports x86-64 and arm64. Although it - should compile on other architectures that implement memory - hot(un)plug, architecture-specific and/or common - code changes may be required for virtio-mem, kdump and kexec to work as - expected. + This driver currently supports x86-64, arm64, riscv and s390. + Although it should compile on other architectures that implement + memory hot(un)plug, architecture-specific and/or common + code changes may be required for virtio-mem, kdump and kexec to + work as expected. If unsure, say M. diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 7315f643817a..e7a917540e2a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1905,7 +1905,7 @@ config STRICT_DEVMEM bool "Filter access to /dev/mem" depends on MMU && DEVMEM depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED - default y if PPC || X86 || ARM64 + default y if PPC || X86 || ARM64 || S390 help If this option is disabled, you allow userspace (root) access to all of memory, including kernel and userspace memory. Accidental |