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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-05 22:17:01 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-05 22:17:01 +0300 |
commit | 493804a6895d63240fe45d087cd14c4b77d8488b (patch) | |
tree | b6d6f91df858d9e1d3857003999cc0a09953322a /arch/s390 | |
parent | 7163a2111f6c030ee39635ac3334bfa1a52a3dd3 (diff) | |
parent | 7a8016d95651fecce5708ed93a24a03a9ad91c80 (diff) | |
download | linux-493804a6895d63240fe45d087cd14c4b77d8488b.tar.xz |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more kvm updates from Paolo Bonzini:
"This includes the 6.4 changes for RISC-V, and a few bugfix patches for
other architectures. For x86, this closes a longstanding performance
issue in the newer and (usually) more scalable page table management
code.
RISC-V:
- ONE_REG interface to enable/disable SBI extensions
- Zbb extension for Guest/VM
- AIA CSR virtualization
x86:
- Fix a long-standing TDP MMU flaw, where unloading roots on a vCPU
can result in the root being freed even though the root is
completely valid and can be reused as-is (with a TLB flush).
s390:
- A couple of bugfixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: fix race in gmap_make_secure()
KVM: s390: pv: fix asynchronous teardown for small VMs
KVM: x86: Preserve TDP MMU roots until they are explicitly invalidated
RISC-V: KVM: Virtualize per-HART AIA CSRs
RISC-V: KVM: Use bitmap for irqs_pending and irqs_pending_mask
RISC-V: KVM: Add ONE_REG interface for AIA CSRs
RISC-V: KVM: Implement subtype for CSR ONE_REG interface
RISC-V: KVM: Initial skeletal support for AIA
RISC-V: KVM: Drop the _MASK suffix from hgatp.VMID mask defines
RISC-V: Detect AIA CSRs from ISA string
RISC-V: Add AIA related CSR defines
RISC-V: KVM: Allow Zbb extension for Guest/VM
RISC-V: KVM: Add ONE_REG interface to enable/disable SBI extensions
RISC-V: KVM: Alphabetize selects
KVM: RISC-V: Retry fault if vma_lookup() results become invalid
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/kernel/uv.c | 32 | ||||
-rw-r--r-- | arch/s390/kvm/pv.c | 5 | ||||
-rw-r--r-- | arch/s390/mm/gmap.c | 7 |
3 files changed, 23 insertions, 21 deletions
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 9f18a4af9c13..cb2ee06df286 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -192,21 +192,10 @@ static int expected_page_refs(struct page *page) return res; } -static int make_secure_pte(pte_t *ptep, unsigned long addr, - struct page *exp_page, struct uv_cb_header *uvcb) +static int make_page_secure(struct page *page, struct uv_cb_header *uvcb) { - pte_t entry = READ_ONCE(*ptep); - struct page *page; int expected, cc = 0; - if (!pte_present(entry)) - return -ENXIO; - if (pte_val(entry) & _PAGE_INVALID) - return -ENXIO; - - page = pte_page(entry); - if (page != exp_page) - return -ENXIO; if (PageWriteback(page)) return -EAGAIN; expected = expected_page_refs(page); @@ -304,17 +293,18 @@ again: goto out; rc = -ENXIO; - page = follow_page(vma, uaddr, FOLL_WRITE); - if (IS_ERR_OR_NULL(page)) - goto out; - - lock_page(page); ptep = get_locked_pte(gmap->mm, uaddr, &ptelock); - if (should_export_before_import(uvcb, gmap->mm)) - uv_convert_from_secure(page_to_phys(page)); - rc = make_secure_pte(ptep, uaddr, page, uvcb); + if (pte_present(*ptep) && !(pte_val(*ptep) & _PAGE_INVALID) && pte_write(*ptep)) { + page = pte_page(*ptep); + rc = -EAGAIN; + if (trylock_page(page)) { + if (should_export_before_import(uvcb, gmap->mm)) + uv_convert_from_secure(page_to_phys(page)); + rc = make_page_secure(page, uvcb); + unlock_page(page); + } + } pte_unmap_unlock(ptep, ptelock); - unlock_page(page); out: mmap_read_unlock(gmap->mm); diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index e032ebbf51b9..3ce5f4351156 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -314,6 +314,11 @@ int kvm_s390_pv_set_aside(struct kvm *kvm, u16 *rc, u16 *rrc) */ if (kvm->arch.pv.set_aside) return -EINVAL; + + /* Guest with segment type ASCE, refuse to destroy asynchronously */ + if ((kvm->arch.gmap->asce & _ASCE_TYPE_MASK) == _ASCE_TYPE_SEGMENT) + return -EINVAL; + priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index dfe905c7bd8e..dc90d1eb0d55 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -2822,6 +2822,9 @@ EXPORT_SYMBOL_GPL(s390_unlist_old_asce); * s390_replace_asce - Try to replace the current ASCE of a gmap with a copy * @gmap: the gmap whose ASCE needs to be replaced * + * If the ASCE is a SEGMENT type then this function will return -EINVAL, + * otherwise the pointers in the host_to_guest radix tree will keep pointing + * to the wrong pages, causing use-after-free and memory corruption. * If the allocation of the new top level page table fails, the ASCE is not * replaced. * In any case, the old ASCE is always removed from the gmap CRST list. @@ -2836,6 +2839,10 @@ int s390_replace_asce(struct gmap *gmap) s390_unlist_old_asce(gmap); + /* Replacing segment type ASCEs would cause serious issues */ + if ((gmap->asce & _ASCE_TYPE_MASK) == _ASCE_TYPE_SEGMENT) + return -EINVAL; + page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER); if (!page) return -ENOMEM; |