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nEPT: Fix test cases for 2M huge pages

PATCH In review Jan Kiszka 2 participants 2 messages Oct 23, 2013 – Oct 28, 2013 KVM

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Jan Kiszka

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#0 lore raw

PATCH 1/1 nEPT: Fix test cases for 2M huge pages

If 2M pages are available with EPT, the test code creates its initial identity map with such pages. But then it tries to remap two 4K pages in that range which fails as their level 3 PTE is set up for huge pages.

Fix this up by ensuring that install_ept_entry always create non-large page directory entries and by remapping the 2M area around those two test pages in 4K chunks.

---
 x86/vmx.c       | 3 ++-
 x86/vmx.h       | 3 ++-
 x86/vmx_tests.c | 8 ++++++++
 3 files changed, 12 insertions(+), 2 deletions(-)
x86/vmx.c +2 -1
index 9db4ef4..3e6fc37 100644
@@ -173,7 +173,8 @@ void install_ept_entry(unsigned long *pml4,
 			memset(new_pt, 0, PAGE_SIZE);
 			pt[offset] = virt_to_phys(new_pt)
 					| EPT_RA | EPT_WA | EPT_EA;
-		}
+		} else
+			pt[offset] &= ~EPT_LARGE_PAGE;
 		pt = phys_to_virt(pt[offset] & 0xffffffffff000ull);
 	}
 	offset = ((unsigned long)guest_addr >> ((level-1) *
x86/vmx.h +2 -1
index dc1ebdf..7d967eb 100644
@@ -485,7 +485,8 @@ enum Ctrl1 {
 #define	EPT_PAGE_LEVEL	4
 #define	EPT_PGDIR_WIDTH	9
 #define	EPT_PGDIR_MASK	511
-#define PAGE_MASK (~(PAGE_SIZE-1))
+#define PAGE_MASK		(~(PAGE_SIZE-1))
+#define PAGE_MASK_2M		(~(PAGE_SIZE_2M-1))
 
 #define EPT_VLT_RD		1
 #define EPT_VLT_WR		(1 << 1)
x86/vmx_tests.c +8 -0
index 0759e10..a002a7a 100644
@@ -915,6 +915,7 @@ static int setup_ept()
 
 static void ept_init()
 {
+	unsigned long base_addr1, base_addr2;
 	u32 ctrl_cpu[2];
 
 	init_fail = false;
@@ -934,6 +935,13 @@ static void ept_init()
 	memset(data_page2, 0x0, PAGE_SIZE);
 	*((u32 *)data_page1) = MAGIC_VAL_1;
 	*((u32 *)data_page2) = MAGIC_VAL_2;
+	base_addr1 = (unsigned long)data_page1 & PAGE_MASK_2M;
+	base_addr2 = (unsigned long)data_page2 & PAGE_MASK_2M;
+	if (setup_ept_range(pml4, base_addr1, base_addr1 + PAGE_SIZE_2M, 0, 0,
+			    EPT_WA | EPT_RA | EPT_EA) ||
+	    setup_ept_range(pml4, base_addr2, base_addr2 + PAGE_SIZE_2M, 0, 0,
+			    EPT_WA | EPT_RA | EPT_EA))
+		init_fail = true;
 	install_ept(pml4, (unsigned long)data_page1, (unsigned long)data_page2,
 			EPT_RA | EPT_WA | EPT_EA);
 }
Signature · 1 line
1.8.1.1.298.ge7eed54
maintainer
#1 lore raw

Il 23/10/2013 15:38, Jan Kiszka ha scritto:

Quoted 60 lines

If 2M pages are available with EPT, the test code creates its initial identity map with such pages. But then it tries to remap two 4K pages in that range which fails as their level 3 PTE is set up for huge pages.

Fix this up by ensuring that install_ept_entry always create non-large page directory entries and by remapping the 2M area around those two test pages in 4K chunks.

---
 x86/vmx.c       | 3 ++-
 x86/vmx.h       | 3 ++-
 x86/vmx_tests.c | 8 ++++++++
 3 files changed, 12 insertions(+), 2 deletions(-)
x86/vmx.c +2 -1
index 9db4ef4..3e6fc37 100644
@@ -173,7 +173,8 @@ void install_ept_entry(unsigned long *pml4,
 			memset(new_pt, 0, PAGE_SIZE);
 			pt[offset] = virt_to_phys(new_pt)
 					| EPT_RA | EPT_WA | EPT_EA;
-		}
+		} else
+			pt[offset] &= ~EPT_LARGE_PAGE;
 		pt = phys_to_virt(pt[offset] & 0xffffffffff000ull);
 	}
 	offset = ((unsigned long)guest_addr >> ((level-1) *
x86/vmx.h +2 -1
index dc1ebdf..7d967eb 100644
@@ -485,7 +485,8 @@ enum Ctrl1 {
 #define	EPT_PAGE_LEVEL	4
 #define	EPT_PGDIR_WIDTH	9
 #define	EPT_PGDIR_MASK	511
-#define PAGE_MASK (~(PAGE_SIZE-1))
+#define PAGE_MASK		(~(PAGE_SIZE-1))
+#define PAGE_MASK_2M		(~(PAGE_SIZE_2M-1))
 
 #define EPT_VLT_RD		1
 #define EPT_VLT_WR		(1 << 1)
x86/vmx_tests.c +1 -0
index 0759e10..a002a7a 100644
@@ -915,6 +915,7 @@ static int setup_ept()
 
 static void ept_init()
 {
+	unsigned long base_addr1, base_addr2;
 	u32 ctrl_cpu[2];
 
 	init_fail = false;
@@ -934,6 +935,13 @@ static void ept_init()
 	memset(data_page2, 0x0, PAGE_SIZE);
 	*((u32 *)data_page1) = MAGIC_VAL_1;
 	*((u32 *)data_page2) = MAGIC_VAL_2;

x86/vmx_tests.c static void ept_init() · line 947

Quoted 10 lines
x86/vmx_tests.c +7 -0
+	base_addr1 = (unsigned long)data_page1 & PAGE_MASK_2M;
+	base_addr2 = (unsigned long)data_page2 & PAGE_MASK_2M;
+	if (setup_ept_range(pml4, base_addr1, base_addr1 + PAGE_SIZE_2M, 0, 0,
+			    EPT_WA | EPT_RA | EPT_EA) ||
+	    setup_ept_range(pml4, base_addr2, base_addr2 + PAGE_SIZE_2M, 0, 0,
+			    EPT_WA | EPT_RA | EPT_EA))
+		init_fail = true;
 	install_ept(pml4, (unsigned long)data_page1, (unsigned long)data_page2,
 			EPT_RA | EPT_WA | EPT_EA);
 }

Applied to kvm-unit-tests.git vmx.

Paolo