[PATCH v3 2/2] xen/PVH: Make GDT selectors PVH-specific

2018-05-17 Thread Boris Ostrovsky 
We don't need to share PVH GDT layout with other GDTs, especially
since we now have a PVH-speciific entry (for stack canary segment).

Define PVH's own selectors.

(As a side effect of this change we are also fixing improper
reference to __KERNEL_CS)

Signed-off-by: Boris Ostrovsky 
---
 arch/x86/xen/xen-pvh.S | 23 +--
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
index 0db540c..f09350a 100644
--- a/arch/x86/xen/xen-pvh.S
+++ b/arch/x86/xen/xen-pvh.S
@@ -54,7 +54,11 @@
  * charge of setting up it's own stack, GDT and IDT.
  */
 
-#define PVH_GDT_ENTRY_CANARY   4
+#define PVH_GDT_ENTRY_CS   1
+#define PVH_GDT_ENTRY_DS   2
+#define PVH_GDT_ENTRY_CANARY   3
+#define PVH_CS_SEL (PVH_GDT_ENTRY_CS * 8)
+#define PVH_DS_SEL (PVH_GDT_ENTRY_DS * 8)
 #define PVH_CANARY_SEL (PVH_GDT_ENTRY_CANARY * 8)
 
 ENTRY(pvh_start_xen)
@@ -62,7 +66,7 @@ ENTRY(pvh_start_xen)
 
lgdt (_pa(gdt))
 
-   mov $(__BOOT_DS),%eax
+   mov $PVH_DS_SEL,%eax
mov %eax,%ds
mov %eax,%es
mov %eax,%ss
@@ -99,7 +103,7 @@ ENTRY(pvh_start_xen)
mov %eax, %cr0
 
/* Jump to 64-bit mode. */
-   ljmp $__KERNEL_CS, $_pa(1f)
+   ljmp $PVH_CS_SEL, $_pa(1f)
 
/* 64-bit entry point. */
.code64
@@ -136,13 +140,13 @@ ENTRY(pvh_start_xen)
or $(X86_CR0_PG | X86_CR0_PE), %eax
mov %eax, %cr0
 
-   ljmp $__BOOT_CS, $1f
+   ljmp $PVH_CS_SEL, $1f
 1:
call xen_prepare_pvh
mov $_pa(pvh_bootparams), %esi
 
/* startup_32 doesn't expect paging and PAE to be on. */
-   ljmp $__BOOT_CS, $_pa(2f)
+   ljmp $PVH_CS_SEL, $_pa(2f)
 2:
mov %cr0, %eax
and $~X86_CR0_PG, %eax
@@ -151,7 +155,7 @@ ENTRY(pvh_start_xen)
and $~X86_CR4_PAE, %eax
mov %eax, %cr4
 
-   ljmp $__BOOT_CS, $_pa(startup_32)
+   ljmp $PVH_CS_SEL, $_pa(startup_32)
 #endif
 END(pvh_start_xen)
 
@@ -163,13 +167,12 @@ gdt:
.word 0
 gdt_start:
.quad 0x/* NULL descriptor */
-   .quad 0x/* reserved */
 #ifdef CONFIG_X86_64
-   .quad GDT_ENTRY(0xa09a, 0, 0xf) /* __KERNEL_CS */
+   .quad GDT_ENTRY(0xa09a, 0, 0xf) /* PVH_CS_SEL */
 #else
-   .quad GDT_ENTRY(0xc09a, 0, 0xf) /* __KERNEL_CS */
+   .quad GDT_ENTRY(0xc09a, 0, 0xf) /* PVH_CS_SEL */
 #endif
-   .quad GDT_ENTRY(0xc092, 0, 0xf) /* __KERNEL_DS */
+   .quad GDT_ENTRY(0xc092, 0, 0xf) /* PVH_DS_SEL */
.quad GDT_ENTRY(0x4090, 0, 0x18)/* PVH_CANARY_SEL */
 gdt_end:
 
-- 
2.9.3

[PATCH v3 2/2] xen/PVH: Make GDT selectors PVH-specific

2018-05-17 Thread Boris Ostrovsky 
We don't need to share PVH GDT layout with other GDTs, especially
since we now have a PVH-speciific entry (for stack canary segment).

Define PVH's own selectors.

(As a side effect of this change we are also fixing improper
reference to __KERNEL_CS)

Signed-off-by: Boris Ostrovsky 
---
 arch/x86/xen/xen-pvh.S | 23 +--
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
index 0db540c..f09350a 100644
--- a/arch/x86/xen/xen-pvh.S
+++ b/arch/x86/xen/xen-pvh.S
@@ -54,7 +54,11 @@
  * charge of setting up it's own stack, GDT and IDT.
  */
 
-#define PVH_GDT_ENTRY_CANARY   4
+#define PVH_GDT_ENTRY_CS   1
+#define PVH_GDT_ENTRY_DS   2
+#define PVH_GDT_ENTRY_CANARY   3
+#define PVH_CS_SEL (PVH_GDT_ENTRY_CS * 8)
+#define PVH_DS_SEL (PVH_GDT_ENTRY_DS * 8)
 #define PVH_CANARY_SEL (PVH_GDT_ENTRY_CANARY * 8)
 
 ENTRY(pvh_start_xen)
@@ -62,7 +66,7 @@ ENTRY(pvh_start_xen)
 
lgdt (_pa(gdt))
 
-   mov $(__BOOT_DS),%eax
+   mov $PVH_DS_SEL,%eax
mov %eax,%ds
mov %eax,%es
mov %eax,%ss
@@ -99,7 +103,7 @@ ENTRY(pvh_start_xen)
mov %eax, %cr0
 
/* Jump to 64-bit mode. */
-   ljmp $__KERNEL_CS, $_pa(1f)
+   ljmp $PVH_CS_SEL, $_pa(1f)
 
/* 64-bit entry point. */
.code64
@@ -136,13 +140,13 @@ ENTRY(pvh_start_xen)
or $(X86_CR0_PG | X86_CR0_PE), %eax
mov %eax, %cr0
 
-   ljmp $__BOOT_CS, $1f
+   ljmp $PVH_CS_SEL, $1f
 1:
call xen_prepare_pvh
mov $_pa(pvh_bootparams), %esi
 
/* startup_32 doesn't expect paging and PAE to be on. */
-   ljmp $__BOOT_CS, $_pa(2f)
+   ljmp $PVH_CS_SEL, $_pa(2f)
 2:
mov %cr0, %eax
and $~X86_CR0_PG, %eax
@@ -151,7 +155,7 @@ ENTRY(pvh_start_xen)
and $~X86_CR4_PAE, %eax
mov %eax, %cr4
 
-   ljmp $__BOOT_CS, $_pa(startup_32)
+   ljmp $PVH_CS_SEL, $_pa(startup_32)
 #endif
 END(pvh_start_xen)
 
@@ -163,13 +167,12 @@ gdt:
.word 0
 gdt_start:
.quad 0x/* NULL descriptor */
-   .quad 0x/* reserved */
 #ifdef CONFIG_X86_64
-   .quad GDT_ENTRY(0xa09a, 0, 0xf) /* __KERNEL_CS */
+   .quad GDT_ENTRY(0xa09a, 0, 0xf) /* PVH_CS_SEL */
 #else
-   .quad GDT_ENTRY(0xc09a, 0, 0xf) /* __KERNEL_CS */
+   .quad GDT_ENTRY(0xc09a, 0, 0xf) /* PVH_CS_SEL */
 #endif
-   .quad GDT_ENTRY(0xc092, 0, 0xf) /* __KERNEL_DS */
+   .quad GDT_ENTRY(0xc092, 0, 0xf) /* PVH_DS_SEL */
.quad GDT_ENTRY(0x4090, 0, 0x18)/* PVH_CANARY_SEL */
 gdt_end:
 
-- 
2.9.3