fe4e771d5c
We used to defer invalidating userspace TLB entries until jumping out of the kernel. This was causing MMU weirdness most easily triggered by using a pipe in the guest, e.g. "dmesg | tail". I believe the problem was that after the guest kernel changed the PID (part of context switch), the old process's mappings were still present, and so copy_to_user() on the "return to new process" path ended up using stale mappings. Testing with large pages (64K) exposed the problem, probably because with 4K pages, pressure on the TLB faulted all process A's mappings out before the guest kernel could insert any for process B. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
50 lines
1.6 KiB
C
50 lines
1.6 KiB
C
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright IBM Corp. 2008
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*
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* Authors: Hollis Blanchard <hollisb@us.ibm.com>
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*/
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#ifndef __ASM_44X_H__
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#define __ASM_44X_H__
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#include <linux/kvm_host.h>
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/* XXX Can't include mmu-44x.h because it redefines struct mm_context. */
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#define PPC44x_TLB_SIZE 64
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struct kvmppc_vcpu_44x {
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/* Unmodified copy of the guest's TLB. */
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struct kvmppc_44x_tlbe guest_tlb[PPC44x_TLB_SIZE];
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/* TLB that's actually used when the guest is running. */
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struct kvmppc_44x_tlbe shadow_tlb[PPC44x_TLB_SIZE];
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/* Pages which are referenced in the shadow TLB. */
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struct page *shadow_pages[PPC44x_TLB_SIZE];
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/* Track which TLB entries we've modified in the current exit. */
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u8 shadow_tlb_mod[PPC44x_TLB_SIZE];
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struct kvm_vcpu vcpu;
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};
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static inline struct kvmppc_vcpu_44x *to_44x(struct kvm_vcpu *vcpu)
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{
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return container_of(vcpu, struct kvmppc_vcpu_44x, vcpu);
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}
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void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 new_pid);
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#endif /* __ASM_44X_H__ */
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