From 7fe28d7e68f92cc3d0668b8f2fbdf5c303ac3022 Mon Sep 17 00:00:00 2001 From: Jing Zhang Date: Thu, 7 Nov 2024 13:41:34 -0800 Subject: [PATCH 1/3] KVM: arm64: vgic-its: Add a data length check in vgic_its_save_* In all the vgic_its_save_*() functinos, they do not check whether the data length is 8 bytes before calling vgic_write_guest_lock. This patch adds the check. To prevent the kernel from being blown up when the fault occurs, KVM_BUG_ON() is used. And the other BUG_ON()s are replaced together. Cc: stable@vger.kernel.org Signed-off-by: Kunkun Jiang [Jing: Update with the new entry read/write helpers] Signed-off-by: Jing Zhang Link: https://lore.kernel.org/r/20241107214137.428439-4-jingzhangos@google.com Signed-off-by: Oliver Upton --- arch/arm64/kvm/vgic/vgic-its.c | 20 ++++++++------------ arch/arm64/kvm/vgic/vgic.h | 23 +++++++++++++++++++++++ 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index ba945ba78cc7..68ba7e2453cd 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -2086,7 +2086,6 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, u32 esz, static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev, struct its_ite *ite, gpa_t gpa, int ite_esz) { - struct kvm *kvm = its->dev->kvm; u32 next_offset; u64 val; @@ -2095,7 +2094,8 @@ static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev, ((u64)ite->irq->intid << KVM_ITS_ITE_PINTID_SHIFT) | ite->collection->collection_id; val = cpu_to_le64(val); - return vgic_write_guest_lock(kvm, gpa, &val, ite_esz); + + return vgic_its_write_entry_lock(its, gpa, val, ite_esz); } /** @@ -2239,7 +2239,6 @@ static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev) static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev, gpa_t ptr, int dte_esz) { - struct kvm *kvm = its->dev->kvm; u64 val, itt_addr_field; u32 next_offset; @@ -2250,7 +2249,8 @@ static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev, (itt_addr_field << KVM_ITS_DTE_ITTADDR_SHIFT) | (dev->num_eventid_bits - 1)); val = cpu_to_le64(val); - return vgic_write_guest_lock(kvm, ptr, &val, dte_esz); + + return vgic_its_write_entry_lock(its, ptr, val, dte_esz); } /** @@ -2437,7 +2437,8 @@ static int vgic_its_save_cte(struct vgic_its *its, ((u64)collection->target_addr << KVM_ITS_CTE_RDBASE_SHIFT) | collection->collection_id); val = cpu_to_le64(val); - return vgic_write_guest_lock(its->dev->kvm, gpa, &val, esz); + + return vgic_its_write_entry_lock(its, gpa, val, esz); } /* @@ -2453,8 +2454,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz) u64 val; int ret; - BUG_ON(esz > sizeof(val)); - ret = kvm_read_guest_lock(kvm, gpa, &val, esz); + ret = vgic_its_read_entry_lock(its, gpa, &val, esz); if (ret) return ret; val = le64_to_cpu(val); @@ -2492,7 +2492,6 @@ static int vgic_its_save_collection_table(struct vgic_its *its) u64 baser = its->baser_coll_table; gpa_t gpa = GITS_BASER_ADDR_48_to_52(baser); struct its_collection *collection; - u64 val; size_t max_size, filled = 0; int ret, cte_esz = abi->cte_esz; @@ -2516,10 +2515,7 @@ static int vgic_its_save_collection_table(struct vgic_its *its) * table is not fully filled, add a last dummy element * with valid bit unset */ - val = 0; - BUG_ON(cte_esz > sizeof(val)); - ret = vgic_write_guest_lock(its->dev->kvm, gpa, &val, cte_esz); - return ret; + return vgic_its_write_entry_lock(its, gpa, 0, cte_esz); } /* diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index f2486b4d9f95..309295f5e1b0 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -146,6 +146,29 @@ static inline int vgic_write_guest_lock(struct kvm *kvm, gpa_t gpa, return ret; } +static inline int vgic_its_read_entry_lock(struct vgic_its *its, gpa_t eaddr, + u64 *eval, unsigned long esize) +{ + struct kvm *kvm = its->dev->kvm; + + if (KVM_BUG_ON(esize != sizeof(*eval), kvm)) + return -EINVAL; + + return kvm_read_guest_lock(kvm, eaddr, eval, esize); + +} + +static inline int vgic_its_write_entry_lock(struct vgic_its *its, gpa_t eaddr, + u64 eval, unsigned long esize) +{ + struct kvm *kvm = its->dev->kvm; + + if (KVM_BUG_ON(esize != sizeof(eval), kvm)) + return -EINVAL; + + return vgic_write_guest_lock(kvm, eaddr, &eval, esize); +} + /* * This struct provides an intermediate representation of the fields contained * in the GICH_VMCR and ICH_VMCR registers, such that code exporting the GIC From e9649129d33dca561305fc590a7c4ba8c3e5675a Mon Sep 17 00:00:00 2001 From: Kunkun Jiang Date: Thu, 7 Nov 2024 13:41:36 -0800 Subject: [PATCH 2/3] KVM: arm64: vgic-its: Clear DTE when MAPD unmaps a device vgic_its_save_device_tables will traverse its->device_list to save DTE for each device. vgic_its_restore_device_tables will traverse each entry of device table and check if it is valid. Restore if valid. But when MAPD unmaps a device, it does not invalidate the corresponding DTE. In the scenario of continuous saves and restores, there may be a situation where a device's DTE is not saved but is restored. This is unreasonable and may cause restore to fail. This patch clears the corresponding DTE when MAPD unmaps a device. Cc: stable@vger.kernel.org Fixes: 57a9a117154c ("KVM: arm64: vgic-its: Device table save/restore") Co-developed-by: Shusen Li Signed-off-by: Shusen Li Signed-off-by: Kunkun Jiang [Jing: Update with entry write helper] Signed-off-by: Jing Zhang Link: https://lore.kernel.org/r/20241107214137.428439-5-jingzhangos@google.com Signed-off-by: Oliver Upton --- arch/arm64/kvm/vgic/vgic-its.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 68ba7e2453cd..b77fa99eafed 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -1139,9 +1139,11 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its, bool valid = its_cmd_get_validbit(its_cmd); u8 num_eventid_bits = its_cmd_get_size(its_cmd); gpa_t itt_addr = its_cmd_get_ittaddr(its_cmd); + int dte_esz = vgic_its_get_abi(its)->dte_esz; struct its_device *device; + gpa_t gpa; - if (!vgic_its_check_id(its, its->baser_device_table, device_id, NULL)) + if (!vgic_its_check_id(its, its->baser_device_table, device_id, &gpa)) return E_ITS_MAPD_DEVICE_OOR; if (valid && num_eventid_bits > VITS_TYPER_IDBITS) @@ -1162,7 +1164,7 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its, * is an error, so we are done in any case. */ if (!valid) - return 0; + return vgic_its_write_entry_lock(its, gpa, 0, dte_esz); device = vgic_its_alloc_device(its, device_id, itt_addr, num_eventid_bits); From 7602ffd1d5e8927fadd5187cb4aed2fdc9c47143 Mon Sep 17 00:00:00 2001 From: Kunkun Jiang Date: Thu, 7 Nov 2024 13:41:37 -0800 Subject: [PATCH 3/3] KVM: arm64: vgic-its: Clear ITE when DISCARD frees an ITE When DISCARD frees an ITE, it does not invalidate the corresponding ITE. In the scenario of continuous saves and restores, there may be a situation where an ITE is not saved but is restored. This is unreasonable and may cause restore to fail. This patch clears the corresponding ITE when DISCARD frees an ITE. Cc: stable@vger.kernel.org Fixes: eff484e0298d ("KVM: arm64: vgic-its: ITT save and restore") Signed-off-by: Kunkun Jiang [Jing: Update with entry write helper] Signed-off-by: Jing Zhang Link: https://lore.kernel.org/r/20241107214137.428439-6-jingzhangos@google.com Signed-off-by: Oliver Upton --- arch/arm64/kvm/vgic/vgic-its.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index b77fa99eafed..198296933e7e 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -782,6 +782,9 @@ static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its, ite = find_ite(its, device_id, event_id); if (ite && its_is_collection_mapped(ite->collection)) { + struct its_device *device = find_its_device(its, device_id); + int ite_esz = vgic_its_get_abi(its)->ite_esz; + gpa_t gpa = device->itt_addr + ite->event_id * ite_esz; /* * Though the spec talks about removing the pending state, we * don't bother here since we clear the ITTE anyway and the @@ -790,7 +793,8 @@ static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its, vgic_its_invalidate_cache(its); its_free_ite(kvm, ite); - return 0; + + return vgic_its_write_entry_lock(its, gpa, 0, ite_esz); } return E_ITS_DISCARD_UNMAPPED_INTERRUPT;