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authorAnshuman Khandual <khandual@linux.vnet.ibm.com>2019-08-19 23:13:19 -0300
committerMichael Ellerman <mpe@ellerman.id.au>2019-08-30 09:55:40 +1000
commitd5394c059da9786043934bed474562cde124e7d3 (patch)
treee5507805d559e0fe4dae9659105fc5ac2e484bca
parentbd104e6db6f0ad124e507a9ecf1a468efe5697db (diff)
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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 <khandual@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820021326.6884-10-bauerman@linux.ibm.com
-rw-r--r--arch/powerpc/include/asm/svm.h5
-rw-r--r--arch/powerpc/platforms/pseries/Makefile1
-rw-r--r--arch/powerpc/platforms/pseries/setup.c5
-rw-r--r--arch/powerpc/platforms/pseries/svm.c40
4 files changed, 50 insertions, 1 deletions
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 <asm/security_features.h>
#include <asm/asm-const.h>
#include <asm/swiotlb.h>
+#include <asm/svm.h>
#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 <khandual@linux.vnet.ibm.com>
+ */
+
+#include <linux/mm.h>
+#include <asm/ultravisor.h>
+
+/* 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);
+ }
+}