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Message-ID: <20150312201746.2953.11716.stgit@joelvm2.amd.com>
Date: Thu, 12 Mar 2015 15:17:46 -0500
From: Joel Schopp <joel.schopp@....com>
To: Gleb Natapov <gleb@...nel.org>,
Paolo Bonzini <pbonzini@...hat.com>, <kvm@...r.kernel.org>
CC: Joerg Roedel <joro@...tes.org>, Borislav Petkov <bp@...en8.de>,
<linux-kernel@...r.kernel.org>,
David Kaplan <david.kaplan@....com>, <rkrcmar@...hat.com>
Subject: [PATCH] kvm: x86: svm: remove SVM_EXIT_READ_CR* intercepts
There isn't really a valid reason for kvm to intercept cr* reads
on svm hardware. The current kvm code just ends up returning
the register
Signed-off-by: Joel Schopp <joel.schopp@....com>
---
arch/x86/kvm/svm.c | 41 ++++-------------------------------------
1 file changed, 4 insertions(+), 37 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index cc618c8..c3d10e6 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1090,9 +1090,6 @@ static void init_vmcb(struct vcpu_svm *svm)
svm->vcpu.fpu_active = 1;
svm->vcpu.arch.hflags = 0;
- set_cr_intercept(svm, INTERCEPT_CR0_READ);
- set_cr_intercept(svm, INTERCEPT_CR3_READ);
- set_cr_intercept(svm, INTERCEPT_CR4_READ);
set_cr_intercept(svm, INTERCEPT_CR0_WRITE);
set_cr_intercept(svm, INTERCEPT_CR3_WRITE);
set_cr_intercept(svm, INTERCEPT_CR4_WRITE);
@@ -1174,7 +1171,6 @@ static void init_vmcb(struct vcpu_svm *svm)
control->nested_ctl = 1;
clr_intercept(svm, INTERCEPT_INVLPG);
clr_exception_intercept(svm, PF_VECTOR);
- clr_cr_intercept(svm, INTERCEPT_CR3_READ);
clr_cr_intercept(svm, INTERCEPT_CR3_WRITE);
save->g_pat = 0x0007040600070406ULL;
save->cr3 = 0;
@@ -2968,29 +2964,10 @@ static int cr_interception(struct vcpu_svm *svm)
kvm_queue_exception(&svm->vcpu, UD_VECTOR);
return 1;
}
- } else { /* mov from cr */
- switch (cr) {
- case 0:
- val = kvm_read_cr0(&svm->vcpu);
- break;
- case 2:
- val = svm->vcpu.arch.cr2;
- break;
- case 3:
- val = kvm_read_cr3(&svm->vcpu);
- break;
- case 4:
- val = kvm_read_cr4(&svm->vcpu);
- break;
- case 8:
- val = kvm_get_cr8(&svm->vcpu);
- break;
- default:
- WARN(1, "unhandled read from CR%d", cr);
- kvm_queue_exception(&svm->vcpu, UD_VECTOR);
- return 1;
- }
- kvm_register_write(&svm->vcpu, reg, val);
+ } else { /* mov from cr, should never trap in svm */
+ WARN(1, "unhandled read from CR%d", cr);
+ kvm_queue_exception(&svm->vcpu, UD_VECTOR);
+ return 1;
}
kvm_complete_insn_gp(&svm->vcpu, err);
@@ -3321,10 +3298,6 @@ static int mwait_interception(struct vcpu_svm *svm)
}
static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
- [SVM_EXIT_READ_CR0] = cr_interception,
- [SVM_EXIT_READ_CR3] = cr_interception,
- [SVM_EXIT_READ_CR4] = cr_interception,
- [SVM_EXIT_READ_CR8] = cr_interception,
[SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception,
[SVM_EXIT_WRITE_CR0] = cr_interception,
[SVM_EXIT_WRITE_CR3] = cr_interception,
@@ -4151,11 +4124,9 @@ static const struct __x86_intercept {
u32 exit_code;
enum x86_intercept_stage stage;
} x86_intercept_map[] = {
- [x86_intercept_cr_read] = POST_EX(SVM_EXIT_READ_CR0),
[x86_intercept_cr_write] = POST_EX(SVM_EXIT_WRITE_CR0),
[x86_intercept_clts] = POST_EX(SVM_EXIT_WRITE_CR0),
[x86_intercept_lmsw] = POST_EX(SVM_EXIT_WRITE_CR0),
- [x86_intercept_smsw] = POST_EX(SVM_EXIT_READ_CR0),
[x86_intercept_dr_read] = POST_EX(SVM_EXIT_READ_DR0),
[x86_intercept_dr_write] = POST_EX(SVM_EXIT_WRITE_DR0),
[x86_intercept_sldt] = POST_EX(SVM_EXIT_LDTR_READ),
@@ -4221,10 +4192,6 @@ static int svm_check_intercept(struct kvm_vcpu *vcpu,
goto out;
switch (icpt_info.exit_code) {
- case SVM_EXIT_READ_CR0:
- if (info->intercept == x86_intercept_cr_read)
- icpt_info.exit_code += info->modrm_reg;
- break;
case SVM_EXIT_WRITE_CR0: {
unsigned long cr0, val;
u64 intercept;
--
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