From a646ef398e72a2ac40bea974808ffcf1bea4e7f4 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 17 May 2019 12:50:43 +0200 Subject: s390/jump_label: replace stop_machine with smp_call_function The use of stop_machine to replace the mask bits of the jump label branch is a very heavy-weight operation. This is in fact not necessary, the mask of the branch can simply be updated, followed by a signal processor to all the other CPUs to force them to pick up the modified instruction. Signed-off-by: Martin Schwidefsky [heiko.carstens@de.ibm.com]: Change jump_label_make_nop() so we get brcl 0,offset instead of brcl 0,0. This makes sure that only the mask part of the instruction gets changed when updated. Signed-off-by: Heiko Carstens --- arch/s390/mm/maccess.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index 818deeb1ebc3..1864a8bb9622 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -52,21 +52,22 @@ static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t siz * Therefore we have a read-modify-write sequence: the function reads eight * bytes from destination at an eight byte boundary, modifies the bytes * requested and writes the result back in a loop. - * - * Note: this means that this function may not be called concurrently on - * several cpus with overlapping words, since this may potentially - * cause data corruption. */ +static DEFINE_SPINLOCK(s390_kernel_write_lock); + void notrace s390_kernel_write(void *dst, const void *src, size_t size) { + unsigned long flags; long copied; + spin_lock_irqsave(&s390_kernel_write_lock, flags); while (size) { copied = s390_kernel_write_odd(dst, src, size); dst += copied; src += copied; size -= copied; } + spin_unlock_irqrestore(&s390_kernel_write_lock, flags); } static int __memcpy_real(void *dest, void *src, size_t count) -- cgit v1.2.3 From 567b722347239484d0b9ab0b42aeb24c1fe6b4e4 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Thu, 4 Apr 2019 02:19:56 -0400 Subject: s390/mm: mmap base does not depend on ADDR_NO_RANDOMIZE personality randomize_stack_top() checks for current task flag PF_RANDOMIZE in order to use stack randomization and PF_RANDOMIZE is set when ADDR_NO_RANDOMIZE is unset, so no need to check for ADDR_NO_RANDOMIZE in stack_maxrandom_size. [heiko.carstens@de.ibm.com]: See also commit 01578e36163c ("x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks") Signed-off-by: Alexandre Ghiti Signed-off-by: Heiko Carstens --- arch/s390/mm/mmap.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index 687f2a4d3459..cbc718ba6d78 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -24,8 +24,6 @@ static unsigned long stack_maxrandom_size(void) { if (!(current->flags & PF_RANDOMIZE)) return 0; - if (current->personality & ADDR_NO_RANDOMIZE) - return 0; return STACK_RND_MASK << PAGE_SHIFT; } -- cgit v1.2.3 From 64e1f0c531d1072cd97939bf0d8df42b26713543 Mon Sep 17 00:00:00 2001 From: Halil Pasic Date: Thu, 13 Sep 2018 18:57:16 +0200 Subject: s390/mm: force swiotlb for protected virtualization On s390, protected virtualization guests have to use bounced I/O buffers. That requires some plumbing. Let us make sure, any device that uses DMA API with direct ops correctly is spared from the problems, that a hypervisor attempting I/O to a non-shared page would bring. Signed-off-by: Halil Pasic Reviewed-by: Claudio Imbrenda Reviewed-by: Michael Mueller Tested-by: Michael Mueller Signed-off-by: Heiko Carstens --- arch/s390/Kconfig | 4 ++++ arch/s390/include/asm/mem_encrypt.h | 17 ++++++++++++++ arch/s390/mm/init.c | 47 +++++++++++++++++++++++++++++++++++++ 3 files changed, 68 insertions(+) create mode 100644 arch/s390/include/asm/mem_encrypt.h (limited to 'arch/s390/mm') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 65522d6956ca..35bb76491600 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -1,4 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 +config ARCH_HAS_MEM_ENCRYPT + def_bool y + config MMU def_bool y @@ -186,6 +189,7 @@ config S390 select VIRT_CPU_ACCOUNTING select ARCH_HAS_SCALED_CPUTIME select HAVE_NMI + select SWIOTLB config SCHED_OMIT_FRAME_POINTER diff --git a/arch/s390/include/asm/mem_encrypt.h b/arch/s390/include/asm/mem_encrypt.h new file mode 100644 index 000000000000..3eb018508190 --- /dev/null +++ b/arch/s390/include/asm/mem_encrypt.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef S390_MEM_ENCRYPT_H__ +#define S390_MEM_ENCRYPT_H__ + +#ifndef __ASSEMBLY__ + +#define sme_me_mask 0ULL + +static inline bool sme_active(void) { return false; } +extern bool sev_active(void); + +int set_memory_encrypted(unsigned long addr, int numpages); +int set_memory_decrypted(unsigned long addr, int numpages); + +#endif /* __ASSEMBLY__ */ + +#endif /* S390_MEM_ENCRYPT_H__ */ diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 14d1eae9fe43..f0bee6af3960 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -29,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -42,6 +44,8 @@ #include #include #include +#include +#include pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir); @@ -128,6 +132,47 @@ void mark_rodata_ro(void) pr_info("Write protected read-only-after-init data: %luk\n", size >> 10); } +int set_memory_encrypted(unsigned long addr, int numpages) +{ + int i; + + /* make specified pages unshared, (swiotlb, dma_free) */ + for (i = 0; i < numpages; ++i) { + uv_remove_shared(addr); + addr += PAGE_SIZE; + } + return 0; +} + +int set_memory_decrypted(unsigned long addr, int numpages) +{ + int i; + /* make specified pages shared (swiotlb, dma_alloca) */ + for (i = 0; i < numpages; ++i) { + uv_set_shared(addr); + addr += PAGE_SIZE; + } + return 0; +} + +/* are we a protected virtualization guest? */ +bool sev_active(void) +{ + return is_prot_virt_guest(); +} + +/* protected virtualization */ +static void pv_init(void) +{ + if (!is_prot_virt_guest()) + return; + + /* make sure bounce buffers are shared */ + swiotlb_init(1); + swiotlb_update_mem_attributes(); + swiotlb_force = SWIOTLB_FORCE; +} + void __init mem_init(void) { cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask); @@ -136,6 +181,8 @@ void __init mem_init(void) set_max_mapnr(max_low_pfn); high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); + pv_init(); + /* Setup guest page hinting */ cmma_init(); -- cgit v1.2.3