From d5394c059da9786043934bed474562cde124e7d3 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Mon, 19 Aug 2019 23:13:19 -0300 Subject: [PATCH] powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL) Secure guests need to share the DTL buffers with the hypervisor. To that end, use a kmem_cache constructor which converts the underlying buddy allocated SLUB cache pages into shared memory. Signed-off-by: Anshuman Khandual Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820021326.6884-10-bauerman@linux.ibm.com --- arch/powerpc/include/asm/svm.h | 5 ++++ arch/powerpc/platforms/pseries/Makefile | 1 + arch/powerpc/platforms/pseries/setup.c | 5 +++- arch/powerpc/platforms/pseries/svm.c | 40 +++++++++++++++++++++++++ 4 files changed, 50 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/platforms/pseries/svm.c diff --git a/arch/powerpc/include/asm/svm.h b/arch/powerpc/include/asm/svm.h index 2689d8d841f8..85580b30aba4 100644 --- a/arch/powerpc/include/asm/svm.h +++ b/arch/powerpc/include/asm/svm.h @@ -15,6 +15,9 @@ static inline bool is_secure_guest(void) return mfmsr() & MSR_S; } +void dtl_cache_ctor(void *addr); +#define get_dtl_cache_ctor() (is_secure_guest() ? dtl_cache_ctor : NULL) + #else /* CONFIG_PPC_SVM */ static inline bool is_secure_guest(void) @@ -22,5 +25,7 @@ static inline bool is_secure_guest(void) return false; } +#define get_dtl_cache_ctor() NULL + #endif /* CONFIG_PPC_SVM */ #endif /* _ASM_POWERPC_SVM_H */ diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile index ab3d59aeacca..a420ef4c9d8e 100644 --- a/arch/powerpc/platforms/pseries/Makefile +++ b/arch/powerpc/platforms/pseries/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_IBMVIO) += vio.o obj-$(CONFIG_IBMEBUS) += ibmebus.o obj-$(CONFIG_PAPR_SCM) += papr_scm.o obj-$(CONFIG_PPC_SPLPAR) += vphn.o +obj-$(CONFIG_PPC_SVM) += svm.o ifdef CONFIG_PPC_PSERIES obj-$(CONFIG_SUSPEND) += suspend.o diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index f5940cc71c37..d8930c3a8a11 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -69,6 +69,7 @@ #include #include #include +#include #include "pseries.h" #include "../../../../drivers/pci/pci.h" @@ -297,8 +298,10 @@ static inline int alloc_dispatch_logs(void) static int alloc_dispatch_log_kmem_cache(void) { + void (*ctor)(void *) = get_dtl_cache_ctor(); + dtl_cache = kmem_cache_create("dtl", DISPATCH_LOG_BYTES, - DISPATCH_LOG_BYTES, 0, NULL); + DISPATCH_LOG_BYTES, 0, ctor); if (!dtl_cache) { pr_warn("Failed to create dispatch trace log buffer cache\n"); pr_warn("Stolen time statistics will be unreliable\n"); diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c new file mode 100644 index 000000000000..2b2b1a77ca1e --- /dev/null +++ b/arch/powerpc/platforms/pseries/svm.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Secure VM platform + * + * Copyright 2018 IBM Corporation + * Author: Anshuman Khandual + */ + +#include +#include + +/* There's one dispatch log per CPU. */ +#define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE) + +static struct page *dtl_page_store[NR_DTL_PAGE]; +static long dtl_nr_pages; + +static bool is_dtl_page_shared(struct page *page) +{ + long i; + + for (i = 0; i < dtl_nr_pages; i++) + if (dtl_page_store[i] == page) + return true; + + return false; +} + +void dtl_cache_ctor(void *addr) +{ + unsigned long pfn = PHYS_PFN(__pa(addr)); + struct page *page = pfn_to_page(pfn); + + if (!is_dtl_page_shared(page)) { + dtl_page_store[dtl_nr_pages] = page; + dtl_nr_pages++; + WARN_ON(dtl_nr_pages >= NR_DTL_PAGE); + uv_share_page(pfn, 1); + } +} -- 2.30.2