Messages in this thread | | | Date | Wed, 27 May 2020 00:56:22 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [RFC 06/16] KVM: Use GUP instead of copy_from/to_user() to access guest memory |
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On Tue, May 26, 2020 at 09:14:59AM +0300, Mike Rapoport wrote: > On Fri, May 22, 2020 at 03:52:04PM +0300, Kirill A. Shutemov wrote: > > New helpers copy_from_guest()/copy_to_guest() to be used if KVM memory > > protection feature is enabled. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > --- > > include/linux/kvm_host.h | 4 +++ > > virt/kvm/kvm_main.c | 78 ++++++++++++++++++++++++++++++++++------ > > 2 files changed, 72 insertions(+), 10 deletions(-) > > > > static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, > > - void *data, int offset, int len) > > + void *data, int offset, int len, > > + bool protected) > > { > > int r; > > unsigned long addr; > > @@ -2257,7 +2297,10 @@ static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, > > addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); > > if (kvm_is_error_hva(addr)) > > return -EFAULT; > > - r = __copy_from_user(data, (void __user *)addr + offset, len); > > + if (protected) > > + r = copy_from_guest(data, addr + offset, len); > > + else > > + r = __copy_from_user(data, (void __user *)addr + offset, len); > > Maybe always use copy_{from,to}_guest() and move the 'if (protected)' > there? > If kvm is added to memory slot, it cab be the passed to copy_{to,from}_guest.
Right, Vitaly has pointed me to this already.
-- Kirill A. Shutemov
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