File 5aec7393-2-x86-xpti-write-cr3.patch of Package xen.8389

From cda05dcae6732fc9c5b782a97a09b5a0f0dd4b81 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@suse.com>
Date: Thu, 26 Apr 2018 13:33:11 +0200
Subject: [PATCH] xen/x86: add a function for modifying cr3

Instead of having multiple places with more or less identical asm
statements just have one function doing a write to cr3.

As this function should be named write_cr3() rename the current
write_cr3() function to switch_cr3().

Suggested-by: Andrew Copper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/x86/flushtlb.c         | 4 ++--
 xen/arch/x86/mm.c               | 2 +-
 xen/arch/x86/pv/domain.c        | 2 +-
 xen/common/efi/runtime.c        | 4 ++--
 xen/include/asm-x86/flushtlb.h  | 2 +-
 xen/include/asm-x86/processor.h | 5 +++++
 6 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/xen/arch/x86/flushtlb.c b/xen/arch/x86/flushtlb.c
index 2729ba42e7..1af9221607 100644
--- a/xen/arch/x86/flushtlb.c
+++ b/xen/arch/x86/flushtlb.c
@@ -72,7 +72,7 @@ static void post_flush(u32 t)
     this_cpu(tlbflush_time) = t;
 }
 
-void write_cr3(unsigned long cr3)
+void switch_cr3(unsigned long cr3)
 {
     unsigned long flags, cr4;
     u32 t;
@@ -84,7 +84,7 @@ void write_cr3(unsigned long cr3)
     cr4 = read_cr4();
 
     write_cr4(cr4 & ~X86_CR4_PGE);
-    asm volatile ( "mov %0, %%cr3" : : "r" (cr3) : "memory" );
+    write_cr3(cr3);
     write_cr4(cr4);
 
     post_flush(t);
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 5373879359..7e2cc924fd 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -509,7 +509,7 @@ void make_cr3(struct vcpu *v, mfn_t mfn)
 void write_ptbase(struct vcpu *v)
 {
     get_cpu_info()->root_pgt_changed = true;
-    write_cr3(v->arch.cr3);
+    switch_cr3(v->arch.cr3);
 }
 
 /*
diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index b1c40373fa..be40843b05 100644
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -247,7 +247,7 @@ static void _toggle_guest_pt(struct vcpu *v)
     get_cpu_info()->root_pgt_changed = true;
 
     /* Don't flush user global mappings from the TLB. Don't tick TLB clock. */
-    asm volatile ( "mov %0, %%cr3" : : "r" (v->arch.cr3) : "memory" );
+    write_cr3(v->arch.cr3);
 
     if ( !(v->arch.flags & TF_kernel_mode) )
         return;
diff --git a/xen/common/efi/runtime.c b/xen/common/efi/runtime.c
index 3dbc2e8ee5..4e5ddfef4f 100644
--- a/xen/common/efi/runtime.c
+++ b/xen/common/efi/runtime.c
@@ -111,7 +111,7 @@ struct efi_rs_state efi_rs_enter(void)
         asm volatile ( "lgdt %0" : : "m" (gdt_desc) );
     }
 
-    write_cr3(virt_to_maddr(efi_l4_pgtable));
+    switch_cr3(virt_to_maddr(efi_l4_pgtable));
 
     return state;
 }
@@ -120,7 +120,7 @@ void efi_rs_leave(struct efi_rs_state *state)
 {
     if ( !state->cr3 )
         return;
-    write_cr3(state->cr3);
+    switch_cr3(state->cr3);
     if ( is_pv_vcpu(current) && !is_idle_vcpu(current) )
     {
         struct desc_ptr gdt_desc = {
diff --git a/xen/include/asm-x86/flushtlb.h b/xen/include/asm-x86/flushtlb.h
index 9b2336c07a..d27906c0ae 100644
--- a/xen/include/asm-x86/flushtlb.h
+++ b/xen/include/asm-x86/flushtlb.h
@@ -84,7 +84,7 @@ static inline unsigned long read_cr3(void)
 }
 
 /* Write pagetable base and implicitly tick the tlbflush clock. */
-void write_cr3(unsigned long cr3);
+void switch_cr3(unsigned long cr3);
 
 /* flush_* flag fields: */
  /*
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 1bc2f90d04..2798db635a 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -293,6 +293,11 @@ static inline unsigned long read_cr2(void)
     return cr2;
 }
 
+static inline void write_cr3(unsigned long val)
+{
+    asm volatile ( "mov %0, %%cr3" : : "r" (val) : "memory" );
+}
+
 static inline unsigned long read_cr4(void)
 {
     return get_cpu_info()->cr4;
-- 
2.11.0