From patchwork Sat May 18 13:54:24 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sanjay Lal X-Patchwork-Id: 2588991 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 45E7940E12 for ; Sat, 18 May 2013 13:54:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752000Ab3ERNyp (ORCPT ); Sat, 18 May 2013 09:54:45 -0400 Received: from kymasys.com ([64.62.140.43]:43263 "HELO kymasys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751975Ab3ERNyh (ORCPT ); Sat, 18 May 2013 09:54:37 -0400 Received: from agni.kymasys.com ([75.40.23.192]) by kymasys.com for ; Sat, 18 May 2013 06:54:36 -0700 Received: by agni.kymasys.com (Postfix, from userid 500) id 52228630051; Sat, 18 May 2013 06:54:28 -0700 (PDT) From: Sanjay Lal To: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org, ralf@linux-mips.org, gleb@redhat.com, mtosatti@redhat.com, Sanjay Lal Subject: [PATCH 2/4] KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock() Date: Sat, 18 May 2013 06:54:24 -0700 Message-Id: <1368885266-8619-3-git-send-email-sanjayl@kymasys.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1368885266-8619-1-git-send-email-sanjayl@kymasys.com> References: <1368885266-8619-1-git-send-email-sanjayl@kymasys.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org - As suggested by Gleb, wrap calls to gfn_to_pfn() with srcu_read_lock/unlock(). Memory slots should be acccessed from a SRCU read section. - kvm_mips_map_page() now returns an error code to it's callers, instead of calling panic() if it cannot find a mapping for a particular gfn. Signed-off-by: Sanjay Lal --- arch/mips/kvm/kvm_tlb.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-) diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c index 89511a9..ab2e9b0 100644 --- a/arch/mips/kvm/kvm_tlb.c +++ b/arch/mips/kvm/kvm_tlb.c @@ -16,7 +16,10 @@ #include #include #include +#include #include +#include + #include #include @@ -169,21 +172,27 @@ void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu) } } -static void kvm_mips_map_page(struct kvm *kvm, gfn_t gfn) +static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn) { + int srcu_idx, err = 0; pfn_t pfn; if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE) - return; + return 0; + srcu_idx = srcu_read_lock(&kvm->srcu); pfn = kvm_mips_gfn_to_pfn(kvm, gfn); if (kvm_mips_is_error_pfn(pfn)) { - panic("Couldn't get pfn for gfn %#" PRIx64 "!\n", gfn); + kvm_err("Couldn't get pfn for gfn %#" PRIx64 "!\n", gfn); + err = -EFAULT; + goto out; } kvm->arch.guest_pmap[gfn] = pfn; - return; +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + return err; } /* Translate guest KSEG0 addresses to Host PA */ @@ -207,7 +216,10 @@ unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu, gva); return KVM_INVALID_PAGE; } - kvm_mips_map_page(vcpu->kvm, gfn); + + if (kvm_mips_map_page(vcpu->kvm, gfn) < 0) + return KVM_INVALID_ADDR; + return (kvm->arch.guest_pmap[gfn] << PAGE_SHIFT) + offset; } @@ -310,8 +322,11 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr, even = !(gfn & 0x1); vaddr = badvaddr & (PAGE_MASK << 1); - kvm_mips_map_page(vcpu->kvm, gfn); - kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1); + if (kvm_mips_map_page(vcpu->kvm, gfn) < 0) + return -1; + + if (kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1) < 0) + return -1; if (even) { pfn0 = kvm->arch.guest_pmap[gfn]; @@ -389,8 +404,11 @@ kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu, pfn0 = 0; pfn1 = 0; } else { - kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0) >> PAGE_SHIFT); - kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1) >> PAGE_SHIFT); + if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0) >> PAGE_SHIFT) < 0) + return -1; + + if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1) >> PAGE_SHIFT) < 0) + return -1; pfn0 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo0) >> PAGE_SHIFT]; pfn1 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo1) >> PAGE_SHIFT];