From: Steven Price steven.price@arm.com
mainline inclusion from mainline-v5.8-rc5 commit cac0f1b7285eaaf9a186c618c3a7304d82ed5493 category: feature bugzilla: NA DTS: NA CVE: NA
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kvm_put_guest() is analogous to put_user() - it writes a single value to the guest physical address. The implementation is built upon put_user() and so it has the same single copy atomic properties.
Signed-off-by: Steven Price steven.price@arm.com Signed-off-by: Marc Zyngier maz@kernel.org --- include/linux/kvm_host.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a0de4c7dc..efd946663 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -727,6 +727,28 @@ int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, unsigned long len); int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len); + +#define __kvm_put_guest(kvm, gfn, offset, value, type) \ +({ \ + unsigned long __addr = gfn_to_hva(kvm, gfn); \ + type __user *__uaddr = (type __user *)(__addr + offset); \ + int __ret = -EFAULT; \ + \ + if (!kvm_is_error_hva(__addr)) \ + __ret = put_user(value, __uaddr); \ + if (!__ret) \ + mark_page_dirty(kvm, gfn); \ + __ret; \ +}) + +#define kvm_put_guest(kvm, gpa, value, type) \ +({ \ + gpa_t __gpa = gpa; \ + struct kvm *__kvm = kvm; \ + __kvm_put_guest(__kvm, __gpa >> PAGE_SHIFT, \ + offset_in_page(__gpa), (value), type); \ +}) + int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len); struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);