Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753859AbbEMGqU (ORCPT ); Wed, 13 May 2015 02:46:20 -0400 Received: from mga03.intel.com ([134.134.136.65]:51206 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752085AbbEMGqO (ORCPT ); Wed, 13 May 2015 02:46:14 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,419,1427785200"; d="scan'208";a="492939122" From: Xiao Guangrong To: pbonzini@redhat.com Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiao Guangrong Subject: [PATCH v3 09/10] KVM: MMU: fix MTRR update Date: Wed, 13 May 2015 14:42:27 +0800 Message-Id: <1431499348-25188-10-git-send-email-guangrong.xiao@linux.intel.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1431499348-25188-1-git-send-email-guangrong.xiao@linux.intel.com> References: <1431499348-25188-1-git-send-email-guangrong.xiao@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2991 Lines: 102 Currently, whenever guest MTRR registers are changed kvm_mmu_reset_context is called to switch to the new root shadow page table, however, it's useless since: 1) the cache type is not cached into shadow page's attribute so that the original root shadow page will be reused 2) the cache type is set on the last spte, that means we should sync the last sptes when MTRR is changed This patch fixs this issue by drop all the spte in the gfn range which is being updated by MTRR Signed-off-by: Xiao Guangrong --- arch/x86/kvm/x86.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 58 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cde5d61..bbe184f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1852,6 +1852,63 @@ bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data) } EXPORT_SYMBOL_GPL(kvm_mtrr_valid); +static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr) +{ + struct mtrr_state_type *mtrr_state = &vcpu->arch.mtrr_state; + unsigned char mtrr_enabled = mtrr_state->enabled; + gfn_t start, end, mask; + int index; + bool is_fixed = true; + + if (msr == MSR_IA32_CR_PAT || !tdp_enabled || + !kvm_arch_has_noncoherent_dma(vcpu->kvm)) + return; + + if (!(mtrr_enabled & 0x2) && msr != MSR_MTRRdefType) + return; + + switch (msr) { + case MSR_MTRRfix64K_00000: + start = 0x0; + end = 0x80000; + break; + case MSR_MTRRfix16K_80000: + start = 0x80000; + end = 0xa0000; + break; + case MSR_MTRRfix16K_A0000: + start = 0xa0000; + end = 0xc0000; + break; + case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000: + index = msr - MSR_MTRRfix4K_C0000; + start = 0xc0000 + index * (32 << 10); + end = start + (32 << 10); + break; + case MSR_MTRRdefType: + is_fixed = false; + start = 0x0; + end = ~0ULL; + break; + default: + /* variable range MTRRs. */ + is_fixed = false; + index = (msr - 0x200) / 2; + start = (((u64)mtrr_state->var_ranges[index].base_hi) << 32) + + (mtrr_state->var_ranges[index].base_lo & PAGE_MASK); + mask = (((u64)mtrr_state->var_ranges[index].mask_hi) << 32) + + (mtrr_state->var_ranges[index].mask_lo & PAGE_MASK); + mask |= ~0ULL << cpuid_maxphyaddr(vcpu); + + end = ((start & mask) | ~mask) + 1; + } + + if (is_fixed && !(mtrr_enabled & 0x1)) + return; + + kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end)); +} + static int set_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 data) { u64 *p = (u64 *)&vcpu->arch.mtrr_state.fixed_ranges; @@ -1885,7 +1942,7 @@ static int set_msr_mtrr(struct kvm_vcpu *vcpu, u32 msr, u64 data) *pt = data; } - kvm_mmu_reset_context(vcpu); + update_mtrr(vcpu, msr); return 0; } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/