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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] x86/S3: Drop {save, restore}_rest_processor_state() completely
commit 4304ff420e51b973ec9eb9dafd64a917dd9c0fb1
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Dec 11 20:59:19 2019 +0000
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Apr 29 14:47:28 2020 +0100
x86/S3: Drop {save,restore}_rest_processor_state() completely
There is no need to save/restore FS/GS/XCR0 state. It will be handled
suitably on the context switch away from the idle.
The CR4 restoration in restore_rest_processor_state() was actually fighting
later code in enter_state() which tried to keep CR4.MCE clear until
everything
was set up. Delete the intermediate restoration, and defer final
restoration
until after MCE is reconfigured.
Restoring PAT can be done earlier, and ideally before paging is enabled. By
moving it into the trampoline during the setup for 64bit, the call can be
dropped from cpu_init(). The EFI path boot path doesn't disable paging, so
make the adjustment when switching onto Xen's pagetables.
The only remaing piece of restoration is load_system_tables(), so suspend.c
can be deleted in its entirety.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/acpi/Makefile | 2 +-
xen/arch/x86/acpi/power.c | 9 ++++----
xen/arch/x86/acpi/suspend.c | 49 -----------------------------------------
xen/arch/x86/acpi/wakeup_prot.S | 4 +---
xen/arch/x86/boot/trampoline.S | 5 +++++
xen/arch/x86/cpu/common.c | 2 --
xen/arch/x86/efi/efi-boot.h | 1 +
7 files changed, 12 insertions(+), 60 deletions(-)
diff --git a/xen/arch/x86/acpi/Makefile b/xen/arch/x86/acpi/Makefile
index 1b9e625713..041377e2bb 100644
--- a/xen/arch/x86/acpi/Makefile
+++ b/xen/arch/x86/acpi/Makefile
@@ -1,4 +1,4 @@
obj-y += cpufreq/
-obj-y += lib.o power.o suspend.o cpu_idle.o cpuidle_menu.o
+obj-y += lib.o power.o cpu_idle.o cpuidle_menu.o
obj-bin-y += boot.init.o wakeup_prot.o
diff --git a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c
index 6dfd4c7891..0cda362045 100644
--- a/xen/arch/x86/acpi/power.c
+++ b/xen/arch/x86/acpi/power.c
@@ -195,7 +195,6 @@ static int enter_state(u32 state)
unsigned long flags;
int error;
struct cpu_info *ci;
- unsigned long cr4;
if ( (state <= ACPI_STATE_S0) || (state > ACPI_S_STATES_MAX) )
return -EINVAL;
@@ -270,15 +269,15 @@ static int enter_state(u32 state)
system_state = SYS_STATE_resume;
- /* Restore CR4 and EFER from cached values. */
- cr4 = read_cr4();
- write_cr4(cr4 & ~X86_CR4_MCE);
+ /* Restore EFER from cached value. */
write_efer(read_efer());
device_power_up(SAVED_ALL);
mcheck_init(&boot_cpu_data, false);
- write_cr4(cr4);
+
+ /* Restore CR4 from cached value, now MCE is set up. */
+ write_cr4(read_cr4());
printk(XENLOG_INFO "Finishing wakeup from ACPI S%d state.\n", state);
diff --git a/xen/arch/x86/acpi/suspend.c b/xen/arch/x86/acpi/suspend.c
deleted file mode 100644
index 3c1a3cbb34..0000000000
--- a/xen/arch/x86/acpi/suspend.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Portions are:
- * Copyright (c) 2002 Pavel Machek <pavel@xxxxxxx>
- * 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/xstate.h>
-#include <xen/hypercall.h>
-
-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);
-
- if ( cpu_has_xsave )
- saved_xcr0 = get_xcr0();
-}
-
-
-void restore_rest_processor_state(void)
-{
- load_system_tables();
-
- /* Restore full CR4 (inc MCE) now that the IDT is in place. */
- write_cr4(mmu_cr4_features);
-
- wrfsbase(saved_fs_base);
- wrgsbase(saved_gs_base);
- wrmsrl(MSR_SHADOW_GS_BASE, saved_kernel_gs_base);
-
- if ( cpu_has_xsave && !set_xcr0(saved_xcr0) )
- BUG();
-
- wrmsrl(MSR_IA32_CR_PAT, XEN_MSR_PAT);
-
- mtrr_bp_restore();
-}
diff --git a/xen/arch/x86/acpi/wakeup_prot.S b/xen/arch/x86/acpi/wakeup_prot.S
index 0ce96e26a9..4dba6020a7 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
@@ -51,7 +49,7 @@ ENTRY(s3_resume)
lretq
1:
- call restore_rest_processor_state
+ call load_system_tables
.Lsuspend_err:
pop %r15
diff --git a/xen/arch/x86/boot/trampoline.S b/xen/arch/x86/boot/trampoline.S
index 18c6638924..662e6bdd3c 100644
--- a/xen/arch/x86/boot/trampoline.S
+++ b/xen/arch/x86/boot/trampoline.S
@@ -91,6 +91,11 @@ trampoline_protmode_entry:
and %edi,%edx
wrmsr
1:
+ /* Set up PAT before enabling paging. */
+ mov $XEN_MSR_PAT & 0xffffffff, %eax
+ mov $XEN_MSR_PAT >> 32, %edx
+ mov $MSR_IA32_CR_PAT, %ecx
+ wrmsr
/* Set up EFER (Extended Feature Enable Register). */
movl $MSR_EFER,%ecx
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 1b33f1ed71..2e9631f6b2 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -790,8 +790,6 @@ void cpu_init(void)
if (opt_cpu_info)
printk("Initializing CPU#%d\n", cpu);
- wrmsrl(MSR_IA32_CR_PAT, XEN_MSR_PAT);
-
/* Install correct page table. */
write_ptbase(current);
diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index a13304201f..176df20c9c 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -242,6 +242,7 @@ static void __init noreturn efi_arch_post_exit_boot(void)
if ( cpu_has_nx )
efer |= EFER_NX;
wrmsrl(MSR_EFER, efer);
+ wrmsrl(MSR_IA32_CR_PAT, XEN_MSR_PAT);
write_cr0(X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | X86_CR0_NE | X86_CR0_WP |
X86_CR0_AM | X86_CR0_PG);
asm volatile ( "mov %[cr4], %%cr4\n\t"
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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