From d215f014b3526a9898d87bfb4b866287f0864cc9 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Fri, 28 Aug 2026 13:54:32 +0200 Subject: [PATCH] KVM: s390: Fix dirty marking in adapter_indicators_set*() When the indicator and/or summary bits are set in the guest, the accessed page was only marked dirty in KVM if the access was performed using the slow path; accesses through the new kvm_arch_set_irq_inatomic fast inject path would not mark the page as dirty. Fix by adding/moving the missing calls to mark_page_dirty(). Note that for the inatomic path set_page_dirty{,_lock}() is not needed as the page stays pinned; the unpin path correctly marks it as dirty. Opportunistically reorder the local variables to be in reverse Christmas tree order and refactor to use guard(). Fixes: 1e95e3bc6b05 ("KVM: s390: Enable adapter_indicators_set to use mapped pages") Signed-off-by: Claudio Imbrenda Message-ID: <20260828115439.145885-2-imbrenda@linux.ibm.com> --- arch/s390/kvm/s390/interrupt.c | 77 +++++++++++++++++----------------- 1 file changed, 39 insertions(+), 38 deletions(-) diff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c index 0381ae981703..49b4e233e791 100644 --- a/arch/s390/kvm/s390/interrupt.c +++ b/arch/s390/kvm/s390/interrupt.c @@ -2984,61 +2984,58 @@ static int adapter_indicators_set(struct kvm *kvm, struct s390_io_adapter *adapter, struct kvm_s390_adapter_int *adapter_int) { - unsigned long bit; - int summary_set, idx; struct s390_map_info *ind_info, *summary_info; - void *map; struct page *ind_page, *summary_page; - unsigned long flags; + unsigned long bit; + int summary_set; + void *map; ind_page = NULL; - spin_lock_irqsave(&adapter->maps_lock, flags); - ind_info = get_map_info(adapter, adapter_int->ind_addr); + scoped_guard(spinlock_irqsave, &adapter->maps_lock) { + ind_info = get_map_info(adapter, adapter_int->ind_addr); + if (ind_info) { + map = page_address(ind_info->page); + bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap); + set_bit(bit, map); + } + } if (!ind_info) { - spin_unlock_irqrestore(&adapter->maps_lock, flags); ind_page = pin_map_page(kvm, adapter_int->ind_addr, 0); if (!ind_page) return -1; - idx = srcu_read_lock(&kvm->srcu); map = page_address(ind_page); bit = get_ind_bit(adapter_int->ind_addr, adapter_int->ind_offset, adapter->swap); set_bit(bit, map); - mark_page_dirty(kvm, adapter_int->ind_gaddr >> PAGE_SHIFT); set_page_dirty_lock(ind_page); - srcu_read_unlock(&kvm->srcu, idx); unpin_user_page(ind_page); - } else { - map = page_address(ind_info->page); - bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap); - set_bit(bit, map); - spin_unlock_irqrestore(&adapter->maps_lock, flags); } + scoped_guard(srcu, &kvm->srcu) + mark_page_dirty(kvm, gpa_to_gfn(adapter_int->ind_gaddr)); - spin_lock_irqsave(&adapter->maps_lock, flags); - summary_info = get_map_info(adapter, adapter_int->summary_addr); + scoped_guard(spinlock_irqsave, &adapter->maps_lock) { + summary_info = get_map_info(adapter, adapter_int->summary_addr); + if (summary_info) { + map = page_address(summary_info->page); + bit = get_ind_bit(summary_info->addr, adapter_int->summary_offset, + adapter->swap); + summary_set = test_and_set_bit(bit, map); + } + } if (!summary_info) { - spin_unlock_irqrestore(&adapter->maps_lock, flags); summary_page = pin_map_page(kvm, adapter_int->summary_addr, 0); if (!summary_page) return -1; - idx = srcu_read_lock(&kvm->srcu); map = page_address(summary_page); bit = get_ind_bit(adapter_int->summary_addr, adapter_int->summary_offset, adapter->swap); summary_set = test_and_set_bit(bit, map); - mark_page_dirty(kvm, adapter_int->summary_gaddr >> PAGE_SHIFT); set_page_dirty_lock(summary_page); - srcu_read_unlock(&kvm->srcu, idx); unpin_user_page(summary_page); - } else { - map = page_address(summary_info->page); - bit = get_ind_bit(summary_info->addr, adapter_int->summary_offset, - adapter->swap); - summary_set = test_and_set_bit(bit, map); - spin_unlock_irqrestore(&adapter->maps_lock, flags); } + scoped_guard(srcu, &kvm->srcu) + mark_page_dirty(kvm, gpa_to_gfn(adapter_int->summary_gaddr)); return summary_set ? 0 : 1; } @@ -3048,26 +3045,29 @@ static int adapter_indicators_set_fast(struct kvm *kvm, struct kvm_s390_adapter_int *adapter_int, int setbit) { + struct s390_map_info *ind_info, *summary_info; unsigned long bit; int summary_set; - struct s390_map_info *ind_info, *summary_info; void *map; - spin_lock(&adapter->maps_lock); + guard(srcu)(&kvm->srcu); + guard(spinlock)(&adapter->maps_lock); + ind_info = get_map_info(adapter, adapter_int->ind_addr); - if (!ind_info) { - spin_unlock(&adapter->maps_lock); + if (!ind_info) return -EWOULDBLOCK; - } + map = page_address(ind_info->page); bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap); - if (setbit) + if (setbit) { set_bit(bit, map); - summary_info = get_map_info(adapter, adapter_int->summary_addr); - if (!summary_info) { - spin_unlock(&adapter->maps_lock); - return -EWOULDBLOCK; + mark_page_dirty(kvm, gpa_to_gfn(adapter_int->ind_gaddr)); } + + summary_info = get_map_info(adapter, adapter_int->summary_addr); + if (!summary_info) + return -EWOULDBLOCK; + map = page_address(summary_info->page); bit = get_ind_bit(summary_info->addr, adapter_int->summary_offset, adapter->swap); @@ -3077,7 +3077,8 @@ static int adapter_indicators_set_fast(struct kvm *kvm, summary_set = test_and_set_bit(bit, map); else summary_set = test_and_clear_bit(bit, map); - spin_unlock(&adapter->maps_lock); + mark_page_dirty(kvm, gpa_to_gfn(adapter_int->summary_gaddr)); + return summary_set ? 0 : 1; }