From: Anshuman Khandual <khand...@linux.vnet.ibm.com> On Ultravisor platform kmem_cache for DTL buffers must use a constructor function which converts the underlying buddy allocated SLUB cache pages into shared memory so that they are accessible to the hypervisor.
Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauer...@linux.ibm.com> --- arch/powerpc/include/asm/svm.h | 1 + arch/powerpc/kernel/svm.c | 30 ++++++++++++++++++++++++++++++ arch/powerpc/platforms/pseries/setup.c | 5 ++++- 3 files changed, 35 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/svm.h b/arch/powerpc/include/asm/svm.h index 95d69e472e52..e00688761704 100644 --- a/arch/powerpc/include/asm/svm.h +++ b/arch/powerpc/include/asm/svm.h @@ -16,6 +16,7 @@ static bool is_svm_platform(void) extern void mem_convert_shared(unsigned long pfn, unsigned long npages); extern void mem_convert_secure(unsigned long pfn, unsigned long npages); +extern void dtl_cache_ctor(void *addr); #else static inline bool is_svm_platform(void) { diff --git a/arch/powerpc/kernel/svm.c b/arch/powerpc/kernel/svm.c index 891db2de8c04..1af5caa955f5 100644 --- a/arch/powerpc/kernel/svm.c +++ b/arch/powerpc/kernel/svm.c @@ -66,3 +66,33 @@ int set_memory_decrypted(unsigned long addr, int numpages) return 0; } + +/* 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); + mem_convert_shared(pfn, PAGE_SIZE); + } +} diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 139f0af6c3d9..50ba77c802d2 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -69,6 +69,7 @@ #include <asm/kexec.h> #include <asm/isa-bridge.h> #include <asm/security_features.h> +#include <asm/svm.h> #include "pseries.h" @@ -288,8 +289,10 @@ static inline int alloc_dispatch_logs(void) static int alloc_dispatch_log_kmem_cache(void) { + void (*ctor)(void *) = is_svm_platform() ? dtl_cache_ctor : NULL; + 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");