[Xen-devel] [PATCH v1] x86/hvm: Expose MSR_SHADOW_GS_BASE

[Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>]

This patch is adding an new param in the hvm_hw_cpu structure
so it can be exposed to user space.

Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c                 | 4 ++++
 xen/include/public/arch-x86/hvm/save.h | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 6cb903d..519333c 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -834,6 +834,8 @@ static int hvm_save_cpu_ctxt(struct domain *d, 
hvm_domain_context_t *h)
         ctxt.gs_base = seg.base;
         ctxt.gs_arbytes = seg.attr;
 
+        rdmsrl(MSR_SHADOW_GS_BASE, ctxt.shadow_gs_base);
+
         hvm_get_segment_register(v, x86_seg_tr, &seg);
         ctxt.tr_sel = seg.sel;
         ctxt.tr_limit = seg.limit;
@@ -1090,6 +1092,8 @@ static int hvm_load_cpu_ctxt(struct domain *d, 
hvm_domain_context_t *h)
     seg.attr = ctxt.gs_arbytes;
     hvm_set_segment_register(v, x86_seg_gs, &seg);
 
+    wrmsrl(MSR_SHADOW_GS_BASE, ctxt.shadow_gs_base);
+
     seg.sel = ctxt.tr_sel;
     seg.limit = ctxt.tr_limit;
     seg.base = ctxt.tr_base;
diff --git a/xen/include/public/arch-x86/hvm/save.h 
b/xen/include/public/arch-x86/hvm/save.h
index fd7bf3f..e6e8e87 100644
--- a/xen/include/public/arch-x86/hvm/save.h
+++ b/xen/include/public/arch-x86/hvm/save.h
@@ -134,6 +134,8 @@ struct hvm_hw_cpu {
     /* msr for em64t */
     uint64_t shadow_gs;
 
+    uint64_t shadow_gs_base;
+
     /* msr content saved/restored. */
     uint64_t msr_flags; /* Obsolete, ignored. */
     uint64_t msr_lstar;
-- 
2.7.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel