[Xen-devel] [PATCH 6/6] x86/suspend: Drop save_rest_processor_state() completely

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Construct the system linkage MSRs using percpu_traps_init(), brining the S3
path in line with the BSP/AP path.  Restore xcr0 from the per-cpu shadow copy.

The FS/GS base values are unused in Xen context, and will be loaded
appropriately by the next vcpu context switch.

Trim the include list substantially, as most are unused.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/acpi/suspend.c     | 54 +++--------------------------------------
 xen/arch/x86/acpi/wakeup_prot.S |  2 --
 2 files changed, 3 insertions(+), 53 deletions(-)

diff --git a/xen/arch/x86/acpi/suspend.c b/xen/arch/x86/acpi/suspend.c
index 32d0f71ffd..629d117965 100644
--- a/xen/arch/x86/acpi/suspend.c
+++ b/xen/arch/x86/acpi/suspend.c
@@ -4,40 +4,8 @@
  *  Copyright (c) 2001 Patrick Mochel <mochel@xxxxxxxx>
  */
 
-#include <xen/acpi.h>
-#include <xen/smp.h>
-#include <asm/processor.h>
-#include <asm/msr.h>
-#include <asm/debugreg.h>
-#include <asm/hvm/hvm.h>
-#include <asm/hvm/support.h>
-#include <asm/i387.h>
+#include <asm/system.h>
 #include <asm/xstate.h>
-#include <xen/hypercall.h>
-
-static unsigned long saved_lstar, saved_cstar;
-static unsigned long saved_sysenter_esp, saved_sysenter_eip;
-static unsigned long saved_fs_base, saved_gs_base, saved_kernel_gs_base;
-static uint64_t saved_xcr0;
-
-void save_rest_processor_state(void)
-{
-    saved_fs_base = rdfsbase();
-    saved_gs_base = rdgsbase();
-    rdmsrl(MSR_SHADOW_GS_BASE, saved_kernel_gs_base);
-    rdmsrl(MSR_CSTAR, saved_cstar);
-    rdmsrl(MSR_LSTAR, saved_lstar);
-
-    if ( cpu_has_sep )
-    {
-        rdmsrl(MSR_IA32_SYSENTER_ESP, saved_sysenter_esp);
-        rdmsrl(MSR_IA32_SYSENTER_EIP, saved_sysenter_eip);
-    }
-
-    if ( cpu_has_xsave )
-        saved_xcr0 = get_xcr0();
-}
-
 
 void restore_rest_processor_state(void)
 {
@@ -46,25 +14,9 @@ void restore_rest_processor_state(void)
     /* Restore full CR4 (inc MCE) now that the IDT is in place. */
     write_cr4(mmu_cr4_features);
 
-    /* Recover syscall MSRs */
-    wrmsrl(MSR_LSTAR, saved_lstar);
-    wrmsrl(MSR_CSTAR, saved_cstar);
-    wrmsrl(MSR_STAR, XEN_MSR_STAR);
-    wrmsrl(MSR_SYSCALL_MASK, XEN_SYSCALL_MASK);
-
-    wrfsbase(saved_fs_base);
-    wrgsbase(saved_gs_base);
-    wrmsrl(MSR_SHADOW_GS_BASE, saved_kernel_gs_base);
-
-    if ( cpu_has_sep )
-    {
-        /* Recover sysenter MSRs */
-        wrmsrl(MSR_IA32_SYSENTER_ESP, saved_sysenter_esp);
-        wrmsrl(MSR_IA32_SYSENTER_EIP, saved_sysenter_eip);
-        wrmsr(MSR_IA32_SYSENTER_CS, __HYPERVISOR_CS, 0);
-    }
+    percpu_traps_init();
 
-    if ( cpu_has_xsave && !set_xcr0(saved_xcr0) )
+    if ( cpu_has_xsave && !set_xcr0(get_xcr0()) )
         BUG();
 
     wrmsrl(MSR_IA32_CR_PAT, XEN_MSR_PAT);
diff --git a/xen/arch/x86/acpi/wakeup_prot.S b/xen/arch/x86/acpi/wakeup_prot.S
index 0ce96e26a9..fed114c0b2 100644
--- a/xen/arch/x86/acpi/wakeup_prot.S
+++ b/xen/arch/x86/acpi/wakeup_prot.S
@@ -15,8 +15,6 @@ ENTRY(do_suspend_lowlevel)
         mov     %cr0, %rax
         mov     %rax, saved_cr0(%rip)
 
-        call    save_rest_processor_state
-
         /* enter sleep state physically */
         mov     $3, %edi
         call    acpi_enter_sleep_state
-- 
2.11.0


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel