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Diffstat (limited to 'arch/mips/kvm/emulate.c')
-rw-r--r--arch/mips/kvm/emulate.c114
1 files changed, 63 insertions, 51 deletions
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index b37954c..396df6e 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -302,12 +302,31 @@ static inline ktime_t kvm_mips_count_time(struct kvm_vcpu *vcpu)
*/
static uint32_t kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now)
{
- ktime_t expires;
+ struct mips_coproc *cop0 = vcpu->arch.cop0;
+ ktime_t expires, threshold;
+ uint32_t count, compare;
int running;
- /* Is the hrtimer pending? */
+ /* Calculate the biased and scaled guest CP0_Count */
+ count = vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
+ compare = kvm_read_c0_guest_compare(cop0);
+
+ /*
+ * Find whether CP0_Count has reached the closest timer interrupt. If
+ * not, we shouldn't inject it.
+ */
+ if ((int32_t)(count - compare) < 0)
+ return count;
+
+ /*
+ * The CP0_Count we're going to return has already reached the closest
+ * timer interrupt. Quickly check if it really is a new interrupt by
+ * looking at whether the interval until the hrtimer expiry time is
+ * less than 1/4 of the timer period.
+ */
expires = hrtimer_get_expires(&vcpu->arch.comparecount_timer);
- if (ktime_compare(now, expires) >= 0) {
+ threshold = ktime_add_ns(now, vcpu->arch.count_period / 4);
+ if (ktime_before(expires, threshold)) {
/*
* Cancel it while we handle it so there's no chance of
* interference with the timeout handler.
@@ -329,8 +348,7 @@ static uint32_t kvm_mips_read_count_running(struct kvm_vcpu *vcpu, ktime_t now)
}
}
- /* Return the biased and scaled guest CP0_Count */
- return vcpu->arch.count_bias + kvm_mips_ktime_to_count(vcpu, now);
+ return count;
}
/**
@@ -420,32 +438,6 @@ static void kvm_mips_resume_hrtimer(struct kvm_vcpu *vcpu,
}
/**
- * kvm_mips_update_hrtimer() - Update next expiry time of hrtimer.
- * @vcpu: Virtual CPU.
- *
- * Recalculates and updates the expiry time of the hrtimer. This can be used
- * after timer parameters have been altered which do not depend on the time that
- * the change occurs (in those cases kvm_mips_freeze_hrtimer() and
- * kvm_mips_resume_hrtimer() are used directly).
- *
- * It is guaranteed that no timer interrupts will be lost in the process.
- *
- * Assumes !kvm_mips_count_disabled(@vcpu) (guest CP0_Count timer is running).
- */
-static void kvm_mips_update_hrtimer(struct kvm_vcpu *vcpu)
-{
- ktime_t now;
- uint32_t count;
-
- /*
- * freeze_hrtimer takes care of a timer interrupts <= count, and
- * resume_hrtimer the hrtimer takes care of a timer interrupts > count.
- */
- now = kvm_mips_freeze_hrtimer(vcpu, &count);
- kvm_mips_resume_hrtimer(vcpu, now, count);
-}
-
-/**
* kvm_mips_write_count() - Modify the count and update timer.
* @vcpu: Virtual CPU.
* @count: Guest CP0_Count value to set.
@@ -540,23 +532,42 @@ int kvm_mips_set_count_hz(struct kvm_vcpu *vcpu, s64 count_hz)
* kvm_mips_write_compare() - Modify compare and update timer.
* @vcpu: Virtual CPU.
* @compare: New CP0_Compare value.
+ * @ack: Whether to acknowledge timer interrupt.
*
* Update CP0_Compare to a new value and update the timeout.
+ * If @ack, atomically acknowledge any pending timer interrupt, otherwise ensure
+ * any pending timer interrupt is preserved.
*/
-void kvm_mips_write_compare(struct kvm_vcpu *vcpu, uint32_t compare)
+void kvm_mips_write_compare(struct kvm_vcpu *vcpu, uint32_t compare, bool ack)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
+ int dc;
+ u32 old_compare = kvm_read_c0_guest_compare(cop0);
+ ktime_t now;
+ uint32_t count;
/* if unchanged, must just be an ack */
- if (kvm_read_c0_guest_compare(cop0) == compare)
+ if (old_compare == compare) {
+ if (!ack)
+ return;
+ kvm_mips_callbacks->dequeue_timer_int(vcpu);
+ kvm_write_c0_guest_compare(cop0, compare);
return;
+ }
+
+ /* freeze_hrtimer() takes care of timer interrupts <= count */
+ dc = kvm_mips_count_disabled(vcpu);
+ if (!dc)
+ now = kvm_mips_freeze_hrtimer(vcpu, &count);
+
+ if (ack)
+ kvm_mips_callbacks->dequeue_timer_int(vcpu);
- /* Update compare */
kvm_write_c0_guest_compare(cop0, compare);
- /* Update timeout if count enabled */
- if (!kvm_mips_count_disabled(vcpu))
- kvm_mips_update_hrtimer(vcpu);
+ /* resume_hrtimer() takes care of timer interrupts > count */
+ if (!dc)
+ kvm_mips_resume_hrtimer(vcpu, now, count);
}
/**
@@ -1068,15 +1079,15 @@ enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
kvm_read_c0_guest_ebase(cop0));
} else if (rd == MIPS_CP0_TLB_HI && sel == 0) {
uint32_t nasid =
- vcpu->arch.gprs[rt] & ASID_MASK;
+ vcpu->arch.gprs[rt] & KVM_ENTRYHI_ASID;
if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) &&
((kvm_read_c0_guest_entryhi(cop0) &
- ASID_MASK) != nasid)) {
+ KVM_ENTRYHI_ASID) != nasid)) {
kvm_debug("MTCz, change ASID from %#lx to %#lx\n",
kvm_read_c0_guest_entryhi(cop0)
- & ASID_MASK,
+ & KVM_ENTRYHI_ASID,
vcpu->arch.gprs[rt]
- & ASID_MASK);
+ & KVM_ENTRYHI_ASID);
/* Blow away the shadow host TLBs */
kvm_mips_flush_host_tlb(1);
@@ -1095,9 +1106,9 @@ enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
/* If we are writing to COMPARE */
/* Clear pending timer interrupt, if any */
- kvm_mips_callbacks->dequeue_timer_int(vcpu);
kvm_mips_write_compare(vcpu,
- vcpu->arch.gprs[rt]);
+ vcpu->arch.gprs[rt],
+ true);
} else if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
unsigned int old_val, val, change;
@@ -1620,7 +1631,7 @@ enum emulation_result kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc,
*/
index = kvm_mips_guest_tlb_lookup(vcpu, (va & VPN2_MASK) |
(kvm_read_c0_guest_entryhi
- (cop0) & ASID_MASK));
+ (cop0) & KVM_ENTRYHI_ASID));
if (index < 0) {
vcpu->arch.host_cp0_entryhi = (va & VPN2_MASK);
@@ -1786,7 +1797,7 @@ enum emulation_result kvm_mips_emulate_tlbmiss_ld(unsigned long cause,
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
unsigned long entryhi = (vcpu->arch. host_cp0_badvaddr & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
+ (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
@@ -1833,7 +1844,7 @@ enum emulation_result kvm_mips_emulate_tlbinv_ld(unsigned long cause,
struct kvm_vcpu_arch *arch = &vcpu->arch;
unsigned long entryhi =
(vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
+ (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
@@ -1878,7 +1889,7 @@ enum emulation_result kvm_mips_emulate_tlbmiss_st(unsigned long cause,
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
+ (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
@@ -1922,7 +1933,7 @@ enum emulation_result kvm_mips_emulate_tlbinv_st(unsigned long cause,
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_vcpu_arch *arch = &vcpu->arch;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
+ (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
/* save old pc */
@@ -1967,7 +1978,7 @@ enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause, uint32_t *opc,
#ifdef DEBUG
struct mips_coproc *cop0 = vcpu->arch.cop0;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
+ (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
int index;
/* If address not in the guest TLB, then we are in trouble */
@@ -1994,7 +2005,7 @@ enum emulation_result kvm_mips_emulate_tlbmod(unsigned long cause,
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
unsigned long entryhi = (vcpu->arch.host_cp0_badvaddr & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(cop0) & ASID_MASK);
+ (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
struct kvm_vcpu_arch *arch = &vcpu->arch;
if ((kvm_read_c0_guest_status(cop0) & ST0_EXL) == 0) {
@@ -2569,7 +2580,8 @@ enum emulation_result kvm_mips_handle_tlbmiss(unsigned long cause,
*/
index = kvm_mips_guest_tlb_lookup(vcpu,
(va & VPN2_MASK) |
- (kvm_read_c0_guest_entryhi(vcpu->arch.cop0) & ASID_MASK));
+ (kvm_read_c0_guest_entryhi(vcpu->arch.cop0) &
+ KVM_ENTRYHI_ASID));
if (index < 0) {
if (exccode == EXCCODE_TLBL) {
er = kvm_mips_emulate_tlbmiss_ld(cause, opc, run, vcpu);
generated by cgit v0.10.2 at 2024-07-10 19:53:27 (GMT)