* [PATCH v2 1/2] KVM: x86: Kill off __ex() and __kvm_handle_fault_on_reboot()
2021-08-09 17:39 [PATCH v2 0/2] KVM: x86: Purge __ex() and __kvm_spurious_fault() Sean Christopherson
@ 2021-08-09 17:39 ` Sean Christopherson
2021-08-09 17:39 ` [PATCH v2 2/2] KVM: x86: Move declaration of kvm_spurious_fault() to x86.h Sean Christopherson
2021-08-10 17:40 ` [PATCH v2 0/2] KVM: x86: Purge __ex() and __kvm_spurious_fault() Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Sean Christopherson @ 2021-08-09 17:39 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel, Uros Bizjak, Like Xu
Remove the __kvm_handle_fault_on_reboot() and __ex() macros now that all
VMX and SVM instructions use asm goto to handle the fault (or in the
case of VMREAD, completely custom logic). Drop kvm_spurious_fault()'s
asmlinkage annotation as __kvm_handle_fault_on_reboot() was the only
flow that invoked it from assembly code.
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Like Xu <like.xu.linux@gmail.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/kvm_host.h | 25 +------------------------
arch/x86/kvm/svm/sev.c | 2 --
arch/x86/kvm/svm/svm.c | 2 --
arch/x86/kvm/vmx/vmx_ops.h | 2 --
arch/x86/kvm/x86.c | 9 ++++++++-
5 files changed, 9 insertions(+), 31 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4c567b05edad..56540b5befd0 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1798,30 +1798,7 @@ enum {
#define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
#define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
-asmlinkage void kvm_spurious_fault(void);
-
-/*
- * Hardware virtualization extension instructions may fault if a
- * reboot turns off virtualization while processes are running.
- * Usually after catching the fault we just panic; during reboot
- * instead the instruction is ignored.
- */
-#define __kvm_handle_fault_on_reboot(insn) \
- "666: \n\t" \
- insn "\n\t" \
- "jmp 668f \n\t" \
- "667: \n\t" \
- "1: \n\t" \
- ".pushsection .discard.instr_begin \n\t" \
- ".long 1b - . \n\t" \
- ".popsection \n\t" \
- "call kvm_spurious_fault \n\t" \
- "1: \n\t" \
- ".pushsection .discard.instr_end \n\t" \
- ".long 1b - . \n\t" \
- ".popsection \n\t" \
- "668: \n\t" \
- _ASM_EXTABLE(666b, 667b)
+void kvm_spurious_fault(void);
#define KVM_ARCH_WANT_MMU_NOTIFIER
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 9f1585f40c85..19cdb73aa623 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -28,8 +28,6 @@
#include "cpuid.h"
#include "trace.h"
-#define __ex(x) __kvm_handle_fault_on_reboot(x)
-
#ifndef CONFIG_KVM_AMD_SEV
/*
* When this config is not defined, SEV feature is not supported and APIs in
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 9d72b1df426e..2b6632d4c76f 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -46,8 +46,6 @@
#include "kvm_onhyperv.h"
#include "svm_onhyperv.h"
-#define __ex(x) __kvm_handle_fault_on_reboot(x)
-
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index 164b64f65a8f..c0d74b994b56 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -10,8 +10,6 @@
#include "evmcs.h"
#include "vmcs.h"
-#define __ex(x) __kvm_handle_fault_on_reboot(x)
-
asmlinkage void vmread_error(unsigned long field, bool fault);
__attribute__((regparm(0))) void vmread_error_trampoline(unsigned long field,
bool fault);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index df71f5e3e23b..156564c34624 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -486,7 +486,14 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
}
EXPORT_SYMBOL_GPL(kvm_set_apic_base);
-asmlinkage __visible noinstr void kvm_spurious_fault(void)
+/*
+ * Handle a fault on a hardware virtualization (VMX or SVM) instruction.
+ *
+ * Hardware virtualization extension instructions may fault if a reboot turns
+ * off virtualization while processes are running. Usually after catching the
+ * fault we just panic; during reboot instead the instruction is ignored.
+ */
+noinstr void kvm_spurious_fault(void)
{
/* Fault while not rebooting. We want the trace. */
BUG_ON(!kvm_rebooting);
--
2.32.0.605.g8dce9f2422-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2 2/2] KVM: x86: Move declaration of kvm_spurious_fault() to x86.h
2021-08-09 17:39 [PATCH v2 0/2] KVM: x86: Purge __ex() and __kvm_spurious_fault() Sean Christopherson
2021-08-09 17:39 ` [PATCH v2 1/2] KVM: x86: Kill off __ex() and __kvm_handle_fault_on_reboot() Sean Christopherson
@ 2021-08-09 17:39 ` Sean Christopherson
2021-08-10 17:40 ` [PATCH v2 0/2] KVM: x86: Purge __ex() and __kvm_spurious_fault() Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Sean Christopherson @ 2021-08-09 17:39 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel, Uros Bizjak, Like Xu
From: Uros Bizjak <ubizjak@gmail.com>
Move the declaration of kvm_spurious_fault() to KVM's "private" x86.h,
it should never be called by anything other than low level KVM code.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
[sean: rebased to a series without __ex()/__kvm_handle_fault_on_reboot()]
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/kvm_host.h | 2 --
arch/x86/kvm/svm/svm_ops.h | 2 +-
arch/x86/kvm/vmx/vmx_ops.h | 2 +-
arch/x86/kvm/x86.h | 2 ++
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 56540b5befd0..45e618902623 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1798,8 +1798,6 @@ enum {
#define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
#define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
-void kvm_spurious_fault(void);
-
#define KVM_ARCH_WANT_MMU_NOTIFIER
int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v);
diff --git a/arch/x86/kvm/svm/svm_ops.h b/arch/x86/kvm/svm/svm_ops.h
index 8170f2a5a16f..22e2b019de37 100644
--- a/arch/x86/kvm/svm/svm_ops.h
+++ b/arch/x86/kvm/svm/svm_ops.h
@@ -4,7 +4,7 @@
#include <linux/compiler_types.h>
-#include <asm/kvm_host.h>
+#include "x86.h"
#define svm_asm(insn, clobber...) \
do { \
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index c0d74b994b56..9e9ef47e988c 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -4,11 +4,11 @@
#include <linux/nospec.h>
-#include <asm/kvm_host.h>
#include <asm/vmx.h>
#include "evmcs.h"
#include "vmcs.h"
+#include "x86.h"
asmlinkage void vmread_error(unsigned long field, bool fault);
__attribute__((regparm(0))) void vmread_error_trampoline(unsigned long field,
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 44ae10312740..7d66d63dc55a 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -8,6 +8,8 @@
#include "kvm_cache_regs.h"
#include "kvm_emulate.h"
+void kvm_spurious_fault(void);
+
static __always_inline void kvm_guest_enter_irqoff(void)
{
/*
--
2.32.0.605.g8dce9f2422-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2 0/2] KVM: x86: Purge __ex() and __kvm_spurious_fault()
2021-08-09 17:39 [PATCH v2 0/2] KVM: x86: Purge __ex() and __kvm_spurious_fault() Sean Christopherson
2021-08-09 17:39 ` [PATCH v2 1/2] KVM: x86: Kill off __ex() and __kvm_handle_fault_on_reboot() Sean Christopherson
2021-08-09 17:39 ` [PATCH v2 2/2] KVM: x86: Move declaration of kvm_spurious_fault() to x86.h Sean Christopherson
@ 2021-08-10 17:40 ` Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2021-08-10 17:40 UTC (permalink / raw)
To: Sean Christopherson
Cc: Vitaly Kuznetsov, Wanpeng Li, Jim Mattson, Joerg Roedel, kvm,
linux-kernel, Uros Bizjak, Like Xu
On 09/08/21 19:39, Sean Christopherson wrote:
> Two patches to remove __ex() and __kvm_spurious_fault(), and hide
> kvm_spurious_fault() in x86.h. These were part of a larger series that
> received the magic "Queued, thanks", but got lost at some point.
>
> v1: https://lore.kernel.org/kvm/20201231002702.2223707-1-seanjc@google.com/
>
> Sean Christopherson (1):
> KVM: x86: Kill off __ex() and __kvm_handle_fault_on_reboot()
>
> Uros Bizjak (1):
> KVM: x86: Move declaration of kvm_spurious_fault() to x86.h
>
> arch/x86/include/asm/kvm_host.h | 25 -------------------------
> arch/x86/kvm/svm/sev.c | 2 --
> arch/x86/kvm/svm/svm.c | 2 --
> arch/x86/kvm/svm/svm_ops.h | 2 +-
> arch/x86/kvm/vmx/vmx_ops.h | 4 +---
> arch/x86/kvm/x86.c | 9 ++++++++-
> arch/x86/kvm/x86.h | 2 ++
> 7 files changed, 12 insertions(+), 34 deletions(-)
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 4+ messages in thread