If there is page fault for secondary mmu, there needs tlb flush
operation indexed with fault gpa address and VMID. VMID is stored
at register CSR_GSTAT and will be reload or recalculated during
guest entry.
Currently CSR_GSTAT is not saved and restored during vcpu context
switch, it is recalculated during guest entry. So CSR_GSTAT is in
effect only when vcpu runs in guest mode, however it may be not in
effected if vcpu exits to host mode, since register CSR_GSTAT may
be stale, it maybe records VMID of last scheduled vcpu, rather than
current vcpu.
Function kvm_flush_tlb_gpa() should be called with its real VMID,
here move it to guest entrance. Also arch specific request id
KVM_REQ_TLB_FLUSH_GPA is added to flush tlb, and it can be optimized
if VMID is updated, since all guest tlb entries will be invalid if
VMID is updated.
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
---
arch/loongarch/include/asm/kvm_host.h | 2 ++
arch/loongarch/kvm/main.c | 1 +
arch/loongarch/kvm/mmu.c | 4 ++--
arch/loongarch/kvm/tlb.c | 5 +----
arch/loongarch/kvm/vcpu.c | 18 ++++++++++++++++++
5 files changed, 24 insertions(+), 6 deletions(-)
diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
index c87b6ea0ec47..32c4948f534f 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -30,6 +30,7 @@
#define KVM_PRIVATE_MEM_SLOTS 0
#define KVM_HALT_POLL_NS_DEFAULT 500000
+#define KVM_REQ_TLB_FLUSH_GPA KVM_ARCH_REQ(0)
#define KVM_GUESTDBG_SW_BP_MASK \
(KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)
@@ -190,6 +191,7 @@ struct kvm_vcpu_arch {
/* vcpu's vpid */
u64 vpid;
+ gpa_t flush_gpa;
/* Frequency of stable timer in Hz */
u64 timer_mhz;
diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
index 86a2f2d0cb27..844736b99d38 100644
--- a/arch/loongarch/kvm/main.c
+++ b/arch/loongarch/kvm/main.c
@@ -242,6 +242,7 @@ void kvm_check_vpid(struct kvm_vcpu *vcpu)
kvm_update_vpid(vcpu, cpu);
trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
vcpu->cpu = cpu;
+ kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
}
/* Restore GSTAT(0x50).vpid */
diff --git a/arch/loongarch/kvm/mmu.c b/arch/loongarch/kvm/mmu.c
index 98883aa23ab8..9e39d28fec35 100644
--- a/arch/loongarch/kvm/mmu.c
+++ b/arch/loongarch/kvm/mmu.c
@@ -908,8 +908,8 @@ int kvm_handle_mm_fault(struct kvm_vcpu *vcpu, unsigned long gpa, bool write)
return ret;
/* Invalidate this entry in the TLB */
- kvm_flush_tlb_gpa(vcpu, gpa);
-
+ vcpu->arch.flush_gpa = gpa;
+ kvm_make_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
return 0;
}
diff --git a/arch/loongarch/kvm/tlb.c b/arch/loongarch/kvm/tlb.c
index 02535df6b51f..ebdbe9264e9c 100644
--- a/arch/loongarch/kvm/tlb.c
+++ b/arch/loongarch/kvm/tlb.c
@@ -23,10 +23,7 @@ void kvm_flush_tlb_all(void)
void kvm_flush_tlb_gpa(struct kvm_vcpu *vcpu, unsigned long gpa)
{
- unsigned long flags;
-
- local_irq_save(flags);
+ lockdep_assert_irqs_disabled();
gpa &= (PAGE_MASK << 1);
invtlb(INVTLB_GID_ADDR, read_csr_gstat() & CSR_GSTAT_GID, gpa);
- local_irq_restore(flags);
}
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 9e8030d45129..b747bd8bc037 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -51,6 +51,16 @@ static int kvm_check_requests(struct kvm_vcpu *vcpu)
return RESUME_GUEST;
}
+static void kvm_late_check_requests(struct kvm_vcpu *vcpu)
+{
+ lockdep_assert_irqs_disabled();
+ if (kvm_check_request(KVM_REQ_TLB_FLUSH_GPA, vcpu))
+ if (vcpu->arch.flush_gpa != INVALID_GPA) {
+ kvm_flush_tlb_gpa(vcpu, vcpu->arch.flush_gpa);
+ vcpu->arch.flush_gpa = INVALID_GPA;
+ }
+}
+
/*
* Check and handle pending signal and vCPU requests etc
* Run with irq enabled and preempt enabled
@@ -101,6 +111,13 @@ static int kvm_pre_enter_guest(struct kvm_vcpu *vcpu)
/* Make sure the vcpu mode has been written */
smp_store_mb(vcpu->mode, IN_GUEST_MODE);
kvm_check_vpid(vcpu);
+
+ /*
+ * Called after function kvm_check_vpid()
+ * Since it updates csr_gstat used by kvm_flush_tlb_gpa(),
+ * also it may clear KVM_REQ_TLB_FLUSH_GPA pending bit
+ */
+ kvm_late_check_requests(vcpu);
vcpu->arch.host_eentry = csr_read64(LOONGARCH_CSR_EENTRY);
/* Clear KVM_LARCH_SWCSR_LATEST as CSR will change when enter guest */
vcpu->arch.aux_inuse &= ~KVM_LARCH_SWCSR_LATEST;
@@ -994,6 +1011,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
struct loongarch_csrs *csr;
vcpu->arch.vpid = 0;
+ vcpu->arch.flush_gpa = INVALID_GPA;
hrtimer_init(&vcpu->arch.swtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
vcpu->arch.swtimer.function = kvm_swtimer_wakeup;
--
2.39.3
