[PATCH V2 03/14] x86/set_memory: Add x86_set_memory_enc static call support

Tianyu Lan
2021-08-04T18:45:43Z

Hyper-V and other platforms(e.g Intel and AMD) want to override
the __set_memory_enc_dec(). Add x86_set_memory_enc static
call here and platforms can hook their implementation.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
arch/x86/include/asm/set_memory.h | 4 ++++
arch/x86/mm/pat/set_memory.c | 9 +++++++++
2 files changed, 13 insertions(+)

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 43fa081a1adb..490f2cfc00fa 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -4,6 +4,7 @@

#include <asm/page.h>
#include <asm-generic/set_memory.h>
+#include <linux/static_call.h>

/*
* The set_memory_* API can be used to change various attributes of a virtual
@@ -84,6 +85,9 @@ int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
bool kernel_page_present(struct page *page);

+int dummy_set_memory_enc(unsigned long addr, int numpages, bool enc);
+DECLARE_STATIC_CALL(x86_set_memory_enc, dummy_set_memory_enc);
+
extern int kernel_set_to_readonly;

#ifdef CONFIG_X86_64
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index ad8a5c586a35..68e9ab522cea 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -18,6 +18,7 @@
#include <linux/libnvdimm.h>
#include <linux/vmstat.h>
#include <linux/kernel.h>
+#include <linux/static_call.h>

#include <asm/e820/api.h>
#include <asm/processor.h>
@@ -66,6 +67,9 @@ static const int cpa_warn_level = CPA_PROTECT;
*/
static DEFINE_SPINLOCK(cpa_lock);

+static int default_set_memory_enc(unsigned long addr, int numpages, bool enc);
+DEFINE_STATIC_CALL(x86_set_memory_enc, default_set_memory_enc);
+
#define CPA_FLUSHTLB 1
#define CPA_ARRAY 2
#define CPA_PAGES_ARRAY 4
@@ -1981,6 +1985,11 @@ int set_memory_global(unsigned long addr, int numpages)
}

static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+{
+ return static_call(x86_set_memory_enc)(addr, numpages, enc);
+}
+
+static int default_set_memory_enc(unsigned long addr, int numpages, bool enc)
{
struct cpa_data cpa;
int ret;
--
2.25.1