From: Paul Durrant Date: Wed, 15 Nov 2023 21:03:32 +0000 (+0000) Subject: stuff X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=0db8c0916d6d6d0a11eb13fb3c976bb598571be1;p=people%2Fpauldu%2Flinux.git stuff Signed-off-by: Paul Durrant --- diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 42a9f1ea25b3..c49441b44477 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -1623,60 +1623,26 @@ static void kvm_xen_check_poller(struct kvm_vcpu *vcpu, int port) } } -/* - * The return value from this function is propagated to kvm_set_irq() API, - * so it returns: - * < 0 Interrupt was ignored (masked or not delivered for other reasons) - * = 0 Interrupt was coalesced (previous irq is still pending) - * > 0 Number of CPUs interrupt was delivered to - * - * It is also called directly from kvm_arch_set_irq_inatomic(), where the - * only check on its return value is a comparison with -EWOULDBLOCK'. - */ -int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) +static int set_shinfo_evtchn_pending(struct kvm_vcpu *vcpu, u32 port) { + struct kvm *kvm = vcpu->kvm; struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache; - struct kvm_vcpu *vcpu; unsigned long *pending_bits, *mask_bits; unsigned long flags; - int port_word_bit; - bool kick_vcpu = false; - int vcpu_idx, idx, rc; - - vcpu_idx = READ_ONCE(xe->vcpu_idx); - if (vcpu_idx >= 0) - vcpu = kvm_get_vcpu(kvm, vcpu_idx); - else { - vcpu = kvm_get_vcpu_by_id(kvm, xe->vcpu_id); - if (!vcpu) - return -EINVAL; - WRITE_ONCE(xe->vcpu_idx, vcpu->vcpu_idx); - } - - if (!vcpu->arch.xen.vcpu_info_cache.active) - return -EINVAL; - - if (xe->port >= max_evtchn_port(kvm)) - return -EINVAL; - - rc = -EWOULDBLOCK; - - idx = srcu_read_lock(&kvm->srcu); + int rc; read_lock_irqsave(&gpc->lock, flags); if (!kvm_gpc_check(gpc, PAGE_SIZE)) - goto out_rcu; + return -EWOULDBLOCK; if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) { struct shared_info *shinfo = gpc->khva; pending_bits = (unsigned long *)&shinfo->evtchn_pending; mask_bits = (unsigned long *)&shinfo->evtchn_mask; - port_word_bit = xe->port / 64; } else { struct compat_shared_info *shinfo = gpc->khva; pending_bits = (unsigned long *)&shinfo->evtchn_pending; mask_bits = (unsigned long *)&shinfo->evtchn_mask; - port_word_bit = xe->port / 32; } /* @@ -1686,28 +1652,42 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) * already set, then we kick the vCPU in question to write to the * *real* evtchn_pending_sel in its own guest vcpu_info struct. */ - if (test_and_set_bit(xe->port, pending_bits)) { + if (test_and_set_bit(port, pending_bits)) { rc = 0; /* It was already raised */ - } else if (test_bit(xe->port, mask_bits)) { + } else if (test_bit(port, mask_bits)) { rc = -ENOTCONN; /* Masked */ - kvm_xen_check_poller(vcpu, xe->port); + kvm_xen_check_poller(vcpu, port); } else { rc = 1; /* Delivered to the bitmap in shared_info. */ - /* Now switch to the vCPU's vcpu_info to set the index and pending_sel */ - read_unlock_irqrestore(&gpc->lock, flags); - gpc = &vcpu->arch.xen.vcpu_info_cache; + } - read_lock_irqsave(&gpc->lock, flags); - if (!kvm_gpc_check(gpc, sizeof(struct vcpu_info))) { - /* - * Could not access the vcpu_info. Set the bit in-kernel - * and prod the vCPU to deliver it for itself. - */ - if (!test_and_set_bit(port_word_bit, &vcpu->arch.xen.evtchn_pending_sel)) - kick_vcpu = true; - goto out_rcu; - } + read_unlock_irqrestore(&gpc->lock, flags); + + return rc; +} + +static bool set_vcpu_info_evtchn_pending(struct kvm_vcpu *vcpu, u32 port) +{ + struct kvm *kvm = vcpu->kvm; + struct gfn_to_pfn_cache *gpc = &vcpu->arch.xen.vcpu_info_cache; + unsigned long flags; + int port_word_bit; + bool kick_vcpu = false; + if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) + port_word_bit = port / 64; + else + port_word_bit = port / 32; + + read_lock_irqsave(&gpc->lock, flags); + if (!kvm_gpc_check(gpc, sizeof(struct vcpu_info))) { + /* + * Could not access the vcpu_info. Set the bit in-kernel + * and prod the vCPU to deliver it for itself. + */ + if (!test_and_set_bit(port_word_bit, &vcpu->arch.xen.evtchn_pending_sel)) + kick_vcpu = true; + } else { if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) { struct vcpu_info *vcpu_info = gpc->khva; if (!test_and_set_bit(port_word_bit, &vcpu_info->evtchn_pending_sel)) { @@ -1730,8 +1710,47 @@ int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) } } - out_rcu: read_unlock_irqrestore(&gpc->lock, flags); + return kick_vcpu; +} +/* + * The return value from this function is propagated to kvm_set_irq() API, + * so it returns: + * < 0 Interrupt was ignored (masked or not delivered for other reasons) + * = 0 Interrupt was coalesced (previous irq is still pending) + * > 0 Number of CPUs interrupt was delivered to + * + * It is also called directly from kvm_arch_set_irq_inatomic(), where the + * only check on its return value is a comparison with -EWOULDBLOCK'. + */ +int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) +{ + int vcpu_idx, idx, rc; + struct kvm_vcpu *vcpu; + bool kick_vcpu = false; + + vcpu_idx = READ_ONCE(xe->vcpu_idx); + if (vcpu_idx >= 0) + vcpu = kvm_get_vcpu(kvm, vcpu_idx); + else { + vcpu = kvm_get_vcpu_by_id(kvm, xe->vcpu_id); + if (!vcpu) + return -EINVAL; + WRITE_ONCE(xe->vcpu_idx, vcpu->vcpu_idx); + } + + if (!vcpu->arch.xen.vcpu_info_cache.active) + return -EINVAL; + + if (xe->port >= max_evtchn_port(kvm)) + return -EINVAL; + + idx = srcu_read_lock(&kvm->srcu); + + rc = set_shinfo_evtchn_pending(vcpu, xe->port); + if (!rc) + kick_vcpu = set_vcpu_info_evtchn_pending(vcpu, xe->port); + srcu_read_unlock(&kvm->srcu, idx); if (kick_vcpu) {