add safe_eoi_write and use from kvm

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 5eb6d56..7c41d3f 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h

@@ -357,12 +357,12 @@
 	u32 (*read)(u32 reg);
 	void (*write)(u32 reg, u32 v);
         /*
-	 * eoi_write has the same signature as write.
-	 * Drivers can support both eoi_write and write by passing the same
-	 * callback value. Kernel can override eoi_write and fall back
-	 * on write for EOI.
+	 * eoi_write, safe_eoi_write and write have the same signature.
+	 * Drivers can support them all by passing the same callback value.
+	 * reg and v will be set to APIC_EOI and APIC_EOI_ACK, respectively.
 	 */
 	void (*eoi_write)(u32 reg, u32 v);
+	void (*safe_eoi_write)(u32 reg, u32 v);
 	u64 (*icr_read)(void);
 	void (*icr_write)(u32 low, u32 high);
 	void (*wait_icr_idle)(void);

diff --git a/arch/x86/kernel/apic/apic_flat_64.c b/arch/x86/kernel/apic/apic_flat_64.c
index 0e881c4..f6628a4 100644
--- a/arch/x86/kernel/apic/apic_flat_64.c
+++ b/arch/x86/kernel/apic/apic_flat_64.c

@@ -228,6 +228,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,
@@ -388,6 +389,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c
index a6e4c6e..2d9e107 100644
--- a/arch/x86/kernel/apic/apic_noop.c
+++ b/arch/x86/kernel/apic/apic_noop.c

@@ -182,6 +182,7 @@
 	.read				= noop_apic_read,
 	.write				= noop_apic_write,
 	.eoi_write			= noop_apic_write,
+	.safe_eoi_write			= noop_apic_write,
 	.icr_read			= noop_apic_icr_read,
 	.icr_write			= noop_apic_icr_write,
 	.wait_icr_idle			= noop_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 6ec6d5d..f44ab30 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c

@@ -296,6 +296,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/bigsmp_32.c b/arch/x86/kernel/apic/bigsmp_32.c
index 31fbdbf..f59e321 100644
--- a/arch/x86/kernel/apic/bigsmp_32.c
+++ b/arch/x86/kernel/apic/bigsmp_32.c

@@ -249,6 +249,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/es7000_32.c b/arch/x86/kernel/apic/es7000_32.c
index db4ab1b..08c9a68 100644
--- a/arch/x86/kernel/apic/es7000_32.c
+++ b/arch/x86/kernel/apic/es7000_32.c

@@ -679,6 +679,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,
@@ -744,6 +745,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/numaq_32.c b/arch/x86/kernel/apic/numaq_32.c
index f00a68cc..4872f57 100644
--- a/arch/x86/kernel/apic/numaq_32.c
+++ b/arch/x86/kernel/apic/numaq_32.c

@@ -531,6 +531,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 1b291da..e18879c 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c

@@ -143,6 +143,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/summit_32.c b/arch/x86/kernel/apic/summit_32.c
index 659897c..3fce4e6 100644
--- a/arch/x86/kernel/apic/summit_32.c
+++ b/arch/x86/kernel/apic/summit_32.c

@@ -547,6 +547,7 @@
 	.read				= native_apic_mem_read,
 	.write				= native_apic_mem_write,
 	.eoi_write			= native_apic_mem_write,
+	.safe_eoi_write			= native_apic_mem_write,
 	.icr_read			= native_apic_icr_read,
 	.icr_write			= native_apic_icr_write,
 	.wait_icr_idle			= native_apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c
index ff35cff..fbf16e6 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c

@@ -261,6 +261,7 @@
 	.read				= native_apic_msr_read,
 	.write				= native_apic_msr_write,
 	.eoi_write			= native_apic_msr_eoi_write,
+	.safe_eoi_write			= native_apic_msr_eoi_write,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
 	.wait_icr_idle			= native_x2apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index c17e982..0fa1f65 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c

@@ -173,6 +173,7 @@
 	.read				= native_apic_msr_read,
 	.write				= native_apic_msr_write,
 	.eoi_write			= native_apic_msr_eoi_write,
+	.safe_eoi_write			= native_apic_msr_eoi_write,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
 	.wait_icr_idle			= native_x2apic_wait_icr_idle,

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index c6d03f7..15e4aad 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c

@@ -405,6 +405,7 @@
 	.read				= native_apic_msr_read,
 	.write				= native_apic_msr_write,
 	.eoi_write			= native_apic_msr_eoi_write,
+	.safe_eoi_write			= native_apic_msr_eoi_write,
 	.icr_read			= native_x2apic_icr_read,
 	.icr_write			= native_x2apic_icr_write,
 	.wait_icr_idle			= native_x2apic_wait_icr_idle,

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index d568060..5fa4af0 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c

@@ -310,7 +310,7 @@
 {
 	if (kvm_test_and_clear_bit(0, &__get_cpu_var(kvm_apic_eoi)))
 		return;
-	apic->write(APIC_EOI, APIC_EOI_ACK);
+	apic->safe_eoi_write(APIC_EOI, APIC_EOI_ACK);
 }
 
 void __cpuinit kvm_guest_cpu_init(void)