From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
"H. Peter Anvin" <hpa@zytor.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
"David P . Reed" <dpreed@deepplum.com>,
Randy Dunlap <rdunlap@infradead.org>,
Uros Bizjak <ubizjak@gmail.com>
Subject: [PATCH 8/9] KVM: x86: Kill off __ex() and __kvm_handle_fault_on_reboot()
Date: Wed, 30 Dec 2020 16:27:01 -0800 [thread overview]
Message-ID: <20201231002702.2223707-9-seanjc@google.com> (raw)
In-Reply-To: <20201231002702.2223707-1-seanjc@google.com>
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>
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 3ab7b46087b7..51ba20ffaedb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1634,30 +1634,7 @@ 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
int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 4511d7ccdb19..e7080e5056a4 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -26,8 +26,6 @@
#include "cpuid.h"
#include "trace.h"
-#define __ex(x) __kvm_handle_fault_on_reboot(x)
-
static u8 sev_enc_bit;
static int sev_flush_asids(void);
static DECLARE_RWSEM(sev_deactivate_lock);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4308ab5ca27e..e4907e490c24 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -43,8 +43,6 @@
#include "svm.h"
#include "svm_ops.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 692b0c31c9c8..7b6fbe103c61 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 3f7c1fc7a3ce..836912b42030 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -412,7 +412,14 @@ 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);
--
2.29.2.729.g45daf8777d-goog
next prev parent reply other threads:[~2020-12-31 0:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-31 0:26 [PATCH 0/9] x86/virt: KVM: x86: Exception handling fixes/cleanups Sean Christopherson
2020-12-31 0:26 ` [PATCH 1/9] x86/virt: Eat faults on VMXOFF in reboot flows Sean Christopherson
2020-12-31 0:26 ` [PATCH 2/9] x86/reboot: Force all cpus to exit VMX root if VMX is supported Sean Christopherson
2020-12-31 0:26 ` [PATCH 3/9] x86/virt: Mark flags and memory as clobbered by VMXOFF Sean Christopherson
2020-12-31 0:26 ` [PATCH 4/9] KVM/nVMX: Use __vmx_vcpu_run in nested_vmx_check_vmentry_hw Sean Christopherson
2020-12-31 0:26 ` [PATCH 5/9] KVM: VMX: Move Intel PT shenanigans out of VMXON/VMXOFF flows Sean Christopherson
2020-12-31 0:26 ` [PATCH 6/9] KVM: VMX: Use the kernel's version of VMXOFF Sean Christopherson
2020-12-31 0:27 ` [PATCH 7/9] KVM: SVM: Use asm goto to handle unexpected #UD on SVM instructions Sean Christopherson
2020-12-31 0:27 ` Sean Christopherson [this message]
2020-12-31 0:27 ` [PATCH 9/9] KVM: x86: Move declaration of kvm_spurious_fault() to x86.h Sean Christopherson
2021-01-27 17:26 ` [PATCH 0/9] x86/virt: KVM: x86: Exception handling fixes/cleanups Paolo Bonzini
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