[PATCH 22/35] kvm, x86: Distinguish dmemfs page from mmio page
From: yulei . kernel
Date: Thu Oct 08 2020 - 03:57:10 EST
From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>
Dmem page is pfn invalid but not mmio. Support cacheable
dmem page for kvm.
Signed-off-by: Chen Zhuo <sagazchen@xxxxxxxxxxx>
Signed-off-by: Yulei Zhang <yuleixzhang@xxxxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 5 +++--
include/linux/dmem.h | 7 +++++++
mm/dmem.c | 7 +++++++
3 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 71aa3da2a0b7..0115c1767063 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -41,6 +41,7 @@
#include <linux/hash.h>
#include <linux/kern_levels.h>
#include <linux/kthread.h>
+#include <linux/dmem.h>
#include <asm/page.h>
#include <asm/memtype.h>
@@ -2962,9 +2963,9 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn)
*/
(!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn));
- return !e820__mapped_raw_any(pfn_to_hpa(pfn),
+ return (!e820__mapped_raw_any(pfn_to_hpa(pfn),
pfn_to_hpa(pfn + 1) - 1,
- E820_TYPE_RAM);
+ E820_TYPE_RAM)) || (!is_dmem_pfn(pfn));
}
/* Bits which may be returned by set_spte() */
diff --git a/include/linux/dmem.h b/include/linux/dmem.h
index 8682d63ed43a..59d3ef14fe42 100644
--- a/include/linux/dmem.h
+++ b/include/linux/dmem.h
@@ -19,11 +19,18 @@ dmem_alloc_pages_vma(struct vm_area_struct *vma, unsigned long addr,
unsigned int try_max, unsigned int *result_nr);
void dmem_free_pages(phys_addr_t addr, unsigned int dpages_nr);
+bool is_dmem_pfn(unsigned long pfn);
#define dmem_free_page(addr) dmem_free_pages(addr, 1)
#else
static inline int dmem_reserve_init(void)
{
return 0;
}
+
+static inline bool is_dmem_pfn(unsigned long pfn)
+{
+ return 0;
+}
+
#endif
#endif /* _LINUX_DMEM_H */
diff --git a/mm/dmem.c b/mm/dmem.c
index 2e61dbddbc62..eb6df7059cf0 100644
--- a/mm/dmem.c
+++ b/mm/dmem.c
@@ -972,3 +972,10 @@ void dmem_free_pages(phys_addr_t addr, unsigned int dpages_nr)
}
EXPORT_SYMBOL(dmem_free_pages);
+bool is_dmem_pfn(unsigned long pfn)
+{
+ struct dmem_node *dnode;
+
+ return !!find_dmem_region(__pfn_to_phys(pfn), &dnode);
+}
+EXPORT_SYMBOL(is_dmem_pfn);
--
2.28.0