This patch removes all the old code which handled the nested
selective cr0 write intercepts. This code was only in place
as a work-around until the instruction emulator is capable
of doing the same. This is the case with this patch-set and
so the code can be removed.
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kvm/svm.c | 78 +++++++++++++++++----------------------------------
1 files changed, 26 insertions(+), 52 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1672e3c..37c0060 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -93,14 +93,6 @@ struct nested_state {
/* A VMEXIT is required but not yet emulated */
bool exit_required;
- /*
- * If we vmexit during an instruction emulation we need this to restore
- * the l1 guest rip after the emulation
- */
- unsigned long vmexit_rip;
- unsigned long vmexit_rsp;
- unsigned long vmexit_rax;
-
/* cache for intercepts of the guest */
u32 intercept_cr;
u32 intercept_dr;
@@ -1365,31 +1357,6 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
struct vcpu_svm *svm = to_svm(vcpu);
- if (is_guest_mode(vcpu)) {
- /*
- * We are here because we run in nested mode, the host kvm
- * intercepts cr0 writes but the l1 hypervisor does not.
- * But the L1 hypervisor may intercept selective cr0 writes.
- * This needs to be checked here.
- */
- unsigned long old, new;
-
- /* Remove bits that would trigger a real cr0 write intercept */
- old = vcpu->arch.cr0 & SVM_CR0_SELECTIVE_MASK;
- new = cr0 & SVM_CR0_SELECTIVE_MASK;
-
- if (old == new) {
- /* cr0 write with ts and mp unchanged */
- svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE;
- if (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE) {
- svm->nested.vmexit_rip = kvm_rip_read(vcpu);
- svm->nested.vmexit_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP);
- svm->nested.vmexit_rax = kvm_register_read(vcpu, VCPU_REGS_RAX);
- return;
- }
- }
- }
-
#ifdef CONFIG_X86_64
if (vcpu->arch.efer & EFER_LME) {
if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
@@ -2676,6 +2643,29 @@ static int emulate_on_interception(struct vcpu_svm *svm)
return emulate_instruction(&svm->vcpu, 0) == EMULATE_DONE;
}
+bool check_selective_cr0_intercepted(struct vcpu_svm *svm, unsigned long val)
+{
+ unsigned long cr0 = svm->vcpu.arch.cr0;
+ bool ret = false;
+ u64 intercept;
+
+ intercept = svm->nested.intercept;
+
+ if (!is_guest_mode(&svm->vcpu) ||
+ (!(intercept & (1ULL << INTERCEPT_SELECTIVE_CR0))))
+ return false;
+
+ cr0 &= ~SVM_CR0_SELECTIVE_MASK;
+ val &= ~SVM_CR0_SELECTIVE_MASK;
+
+ if (cr0 ^ val) {
+ svm->vmcb->control.exit_code = SVM_EXIT_CR0_SEL_WRITE;
+ ret = (nested_svm_exit_handled(svm) == NESTED_EXIT_DONE);
+ }
+
+ return ret;
+}
+
#define CR_VALID (1ULL << 63)
static int cr_interception(struct vcpu_svm *svm)
@@ -2699,7 +2689,8 @@ static int cr_interception(struct vcpu_svm *svm)
val = kvm_register_read(&svm->vcpu, reg);
switch (cr) {
case 0:
- err = kvm_set_cr0(&svm->vcpu, val);
+ if (!check_selective_cr0_intercepted(svm, val))
+ err = kvm_set_cr0(&svm->vcpu, val);
break;
case 3:
err = kvm_set_cr3(&svm->vcpu, val);
@@ -2744,23 +2735,6 @@ static int cr_interception(struct vcpu_svm *svm)
return 1;
}
-static int cr0_write_interception(struct vcpu_svm *svm)
-{
- struct kvm_vcpu *vcpu = &svm->vcpu;
- int r;
-
- r = cr_interception(svm);
-
- if (svm->nested.vmexit_rip) {
- kvm_register_write(vcpu, VCPU_REGS_RIP, svm->nested.vmexit_rip);
- kvm_register_write(vcpu, VCPU_REGS_RSP, svm->nested.vmexit_rsp);
- kvm_register_write(vcpu, VCPU_REGS_RAX, svm->nested.vmexit_rax);
- svm->nested.vmexit_rip = 0;
- }
-
- return r;
-}
-
static int dr_interception(struct vcpu_svm *svm)
{
int reg, dr;
@@ -3048,7 +3022,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = {
[SVM_EXIT_READ_CR4] = cr_interception,
[SVM_EXIT_READ_CR8] = cr_interception,
[SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception,
- [SVM_EXIT_WRITE_CR0] = cr0_write_interception,
+ [SVM_EXIT_WRITE_CR0] = cr_interception,
[SVM_EXIT_WRITE_CR3] = cr_interception,
[SVM_EXIT_WRITE_CR4] = cr_interception,
[SVM_EXIT_WRITE_CR8] = cr8_write_interception,
--
1.7.1
--
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