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KVM: SVM: move special nested exit handling to separate function
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This patch moves the handling for special nested vmexits like #pf to a
separate function. This makes the kvm_override parameter obsolete and
makes the code more readable.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
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Joerg Roedel authored and Avi Kivity committed Sep 10, 2009
1 parent 1f8da47 commit 410e4d5
Showing 1 changed file with 50 additions and 30 deletions.
80 changes: 50 additions & 30 deletions arch/x86/kvm/svm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,10 @@ MODULE_LICENSE("GPL");
#define SVM_FEATURE_LBRV (1 << 1)
#define SVM_FEATURE_SVML (1 << 2)

#define NESTED_EXIT_HOST 0 /* Exit handled on host level */
#define NESTED_EXIT_DONE 1 /* Exit caused nested vmexit */
#define NESTED_EXIT_CONTINUE 2 /* Further checks needed */

#define DEBUGCTL_RESERVED_BITS (~(0x3fULL))

/* Turn on to get debugging output*/
Expand Down Expand Up @@ -126,7 +130,7 @@ module_param(nested, int, S_IRUGO);
static void svm_flush_tlb(struct kvm_vcpu *vcpu);
static void svm_complete_interrupts(struct vcpu_svm *svm);

static int nested_svm_exit_handled(struct vcpu_svm *svm, bool kvm_override);
static int nested_svm_exit_handled(struct vcpu_svm *svm);
static int nested_svm_vmexit(struct vcpu_svm *svm);
static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
bool has_error_code, u32 error_code);
Expand Down Expand Up @@ -1365,7 +1369,7 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
svm->vmcb->control.exit_info_1 = error_code;
svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;

return nested_svm_exit_handled(svm, false);
return nested_svm_exit_handled(svm);
}

static inline int nested_svm_intr(struct vcpu_svm *svm)
Expand All @@ -1379,7 +1383,7 @@ static inline int nested_svm_intr(struct vcpu_svm *svm)

svm->vmcb->control.exit_code = SVM_EXIT_INTR;

if (nested_svm_exit_handled(svm, false)) {
if (nested_svm_exit_handled(svm)) {
nsvm_printk("VMexit -> INTR\n");
return 1;
}
Expand Down Expand Up @@ -1465,74 +1469,82 @@ static bool nested_svm_exit_handled_msr(struct vcpu_svm *svm)
return ret;
}

static int nested_svm_exit_handled(struct vcpu_svm *svm, bool kvm_override)
static int nested_svm_exit_special(struct vcpu_svm *svm)
{
u32 exit_code = svm->vmcb->control.exit_code;
bool vmexit = false;

if (kvm_override) {
switch (exit_code) {
case SVM_EXIT_INTR:
case SVM_EXIT_NMI:
return 0;
switch (exit_code) {
case SVM_EXIT_INTR:
case SVM_EXIT_NMI:
return NESTED_EXIT_HOST;
/* For now we are always handling NPFs when using them */
case SVM_EXIT_NPF:
if (npt_enabled)
return 0;
break;
/* When we're shadowing, trap PFs */
case SVM_EXIT_EXCP_BASE + PF_VECTOR:
if (!npt_enabled)
return 0;
break;
default:
break;
}
case SVM_EXIT_NPF:
if (npt_enabled)
return NESTED_EXIT_HOST;
break;
/* When we're shadowing, trap PFs */
case SVM_EXIT_EXCP_BASE + PF_VECTOR:
if (!npt_enabled)
return NESTED_EXIT_HOST;
break;
default:
break;
}

return NESTED_EXIT_CONTINUE;
}

/*
* If this function returns true, this #vmexit was already handled
*/
static int nested_svm_exit_handled(struct vcpu_svm *svm)
{
u32 exit_code = svm->vmcb->control.exit_code;
int vmexit = NESTED_EXIT_HOST;

switch (exit_code) {
case SVM_EXIT_MSR:
vmexit = nested_svm_exit_handled_msr(svm);
break;
case SVM_EXIT_READ_CR0 ... SVM_EXIT_READ_CR8: {
u32 cr_bits = 1 << (exit_code - SVM_EXIT_READ_CR0);
if (svm->nested.intercept_cr_read & cr_bits)
vmexit = true;
vmexit = NESTED_EXIT_DONE;
break;
}
case SVM_EXIT_WRITE_CR0 ... SVM_EXIT_WRITE_CR8: {
u32 cr_bits = 1 << (exit_code - SVM_EXIT_WRITE_CR0);
if (svm->nested.intercept_cr_write & cr_bits)
vmexit = true;
vmexit = NESTED_EXIT_DONE;
break;
}
case SVM_EXIT_READ_DR0 ... SVM_EXIT_READ_DR7: {
u32 dr_bits = 1 << (exit_code - SVM_EXIT_READ_DR0);
if (svm->nested.intercept_dr_read & dr_bits)
vmexit = true;
vmexit = NESTED_EXIT_DONE;
break;
}
case SVM_EXIT_WRITE_DR0 ... SVM_EXIT_WRITE_DR7: {
u32 dr_bits = 1 << (exit_code - SVM_EXIT_WRITE_DR0);
if (svm->nested.intercept_dr_write & dr_bits)
vmexit = true;
vmexit = NESTED_EXIT_DONE;
break;
}
case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
u32 excp_bits = 1 << (exit_code - SVM_EXIT_EXCP_BASE);
if (svm->nested.intercept_exceptions & excp_bits)
vmexit = true;
vmexit = NESTED_EXIT_DONE;
break;
}
default: {
u64 exit_bits = 1ULL << (exit_code - SVM_EXIT_INTR);
nsvm_printk("exit code: 0x%x\n", exit_code);
if (svm->nested.intercept & exit_bits)
vmexit = true;
vmexit = NESTED_EXIT_DONE;
}
}

if (vmexit) {
if (vmexit == NESTED_EXIT_DONE) {
nsvm_printk("#VMEXIT reason=%04x\n", exit_code);
nested_svm_vmexit(svm);
}
Expand Down Expand Up @@ -2312,10 +2324,18 @@ static int handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
trace_kvm_exit(exit_code, svm->vmcb->save.rip);

if (is_nested(svm)) {
int vmexit;

nsvm_printk("nested handle_exit: 0x%x | 0x%lx | 0x%lx | 0x%lx\n",
exit_code, svm->vmcb->control.exit_info_1,
svm->vmcb->control.exit_info_2, svm->vmcb->save.rip);
if (nested_svm_exit_handled(svm, true))

vmexit = nested_svm_exit_special(svm);

if (vmexit == NESTED_EXIT_CONTINUE)
vmexit = nested_svm_exit_handled(svm);

if (vmexit == NESTED_EXIT_DONE)
return 1;
}

Expand Down

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