Merge tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 retbleed fixes from Borislav Petkov:
 "Just when you thought that all the speculation bugs were addressed and
  solved and the nightmare is complete, here's the next one: speculating
  after RET instructions and leaking privileged information using the
  now pretty much classical covert channels.

  It is called RETBleed and the mitigation effort and controlling
  functionality has been modelled similar to what already existing
  mitigations provide"

* tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
  x86/speculation: Disable RRSBA behavior
  x86/kexec: Disable RET on kexec
  x86/bugs: Do not enable IBPB-on-entry when IBPB is not supported
  x86/entry: Move PUSH_AND_CLEAR_REGS() back into error_entry
  x86/bugs: Add Cannon lake to RETBleed affected CPU list
  x86/retbleed: Add fine grained Kconfig knobs
  x86/cpu/amd: Enumerate BTC_NO
  x86/common: Stamp out the stepping madness
  KVM: VMX: Prevent RSB underflow before vmenter
  x86/speculation: Fill RSB on vmexit for IBRS
  KVM: VMX: Fix IBRS handling after vmexit
  KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS
  KVM: VMX: Convert launched argument to flags
  KVM: VMX: Flatten __vmx_vcpu_run()
  objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}
  x86/speculation: Remove x86_spec_ctrl_mask
  x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit
  x86/speculation: Fix SPEC_CTRL write on SMT state change
  x86/speculation: Fix firmware entry SPEC_CTRL handling
  x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n
  ...

3 files changed, 10 insertions, 3 deletions

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 2c7477354744..314802f98b9d 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -68,6 +68,8 @@ extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr,
 extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
 					struct device_attribute *attr,
 					char *buf);
+extern ssize_t cpu_show_retbleed(struct device *dev,
+				 struct device_attribute *attr, char *buf);
 
 extern __printf(4, 5)
 struct device *cpu_device_create(struct device *parent, void *drvdata,
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c20f2d55840c..83cf7fd842e0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1513,7 +1513,7 @@ static inline void kvm_arch_end_assignment(struct kvm *kvm)
 {
 }
 
-static inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
+static __always_inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
 {
 	return false;
 }
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 15b940ec1eac..10bc88cc3bf6 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -32,11 +32,16 @@ struct unwind_hint {
  *
  * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
  * Useful for code which doesn't have an ELF function annotation.
+ *
+ * UNWIND_HINT_ENTRY: machine entry without stack, SYSCALL/SYSENTER etc.
  */
 #define UNWIND_HINT_TYPE_CALL		0
 #define UNWIND_HINT_TYPE_REGS		1
 #define UNWIND_HINT_TYPE_REGS_PARTIAL	2
 #define UNWIND_HINT_TYPE_FUNC		3
+#define UNWIND_HINT_TYPE_ENTRY		4
+#define UNWIND_HINT_TYPE_SAVE		5
+#define UNWIND_HINT_TYPE_RESTORE	6
 
 #ifdef CONFIG_OBJTOOL
 
@@ -124,7 +129,7 @@ struct unwind_hint {
  * the debuginfo as necessary.  It will also warn if it sees any
  * inconsistencies.
  */
-.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 end=0
 .Lunwind_hint_ip_\@:
 	.pushsection .discard.unwind_hints
 		/* struct unwind_hint */
@@ -177,7 +182,7 @@ struct unwind_hint {
 #define ASM_REACHABLE
 #else
 #define ANNOTATE_INTRA_FUNCTION_CALL
-.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 end=0
 .endm
 .macro STACK_FRAME_NON_STANDARD func:req
 .endm