From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x224onnmIjabCKEMupf8EFqgxpIJe1mIiZPHUasd4vDxHH1Y6L3QEsOvoWmbdX3QkEQ1axees ARC-Seal: i=1; a=rsa-sha256; t=1517591412; cv=none; d=google.com; s=arc-20160816; b=XKGx2x84fJ1/6ZkmV+uaIZnZ0H6KHA+CI2+9wFsG9THfd9swEJHiJfPs/FaTQRZO49 WUXEXjT5/rUaaiBFdUE5DDrtAiq9LB3xlEwdTW679G0bVwMnOxISf0YbaCZj/2nWP1J5 KSkyeYVB4VHzXiCG40NHupNpUwr01kffnfoNkdx3Jv6CJ5sAAaBDyX9JpjDGKA9gfy2v mDbSAwUGhqj1kFWaXK3hDXm9X516GBvy/rwSByQilZMeDNl933Bl7FN3qT6SeS1WOeZ6 KbeBcP/OBND4/0zZNCocKsRFBVA8K/3sJ38SJ5SoLdBlhMSNHs2MbQH51cQJBcJBbE4L 11qg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=ZxqOvjEEN5x5S5ppgGSqLaNjETdqAp71JM2rj7ppSNc=; b=qCo6F9mcWTcuKX8qy0UHNDuc/7z/0WbXq8wQcD6L/2U0dyTv4pt3/k9Z7EnQOftWOX 5zyjnqjMyWunMISu+1M0MPjNhdCkazVgmBTu2QKA6cfRtjhF8JL2zHgiwihO2hJfLE5p COMLjkUfKvV9rdPEIZKw3bda6aP+Vlmh8ZGslfS+3XCPrmD1e+FsEydj9h2qfLPNMVW/ sKHDPzlb5803lbBcFtCcxndu1NjEwZeVSZw18hX8l8440nbwVHOJCPoqsILroqSgYoL0 cBXNsqXWL8kvzcPu20iBSbXgLjSr/UpABLNwIDSHZCCzcP2w0JZmpma92lmp+SNim0DX OrUA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Liran Alon , Nikita Leshenko , Konrad Rzeszutek Wilk , Paolo Bonzini , Wanpeng Li , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Sasha Levin Subject: [PATCH 4.14 036/156] KVM: nVMX/nSVM: Dont intercept #UD when running L2 Date: Fri, 2 Feb 2018 17:56:57 +0100 Message-Id: <20180202140841.939284771@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180202140840.242829545@linuxfoundation.org> References: <20180202140840.242829545@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1591309933569328457?= X-GMAIL-MSGID: =?utf-8?q?1591309933569328457?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liran Alon [ Upstream commit ac9b305caa0df6f5b75d294e4b86c1027648991e ] When running L2, #UD should be intercepted by L1 or just forwarded directly to L2. It should not reach L0 x86 emulator. Therefore, set intercept for #UD only based on L1 exception-bitmap. Also add WARN_ON_ONCE() on L0 #UD intercept handlers to make sure it is never reached while running L2. This improves commit ae1f57670703 ("KVM: nVMX: Do not emulate #UD while in guest mode") by removing an unnecessary exit from L2 to L0 on #UD when L1 doesn't intercept it. In addition, SVM L0 #UD intercept handler doesn't handle correctly the case it is raised from L2. In this case, it should forward the #UD to guest instead of x86 emulator. As done in VMX #UD intercept handler. This commit fixes this issue as-well. Signed-off-by: Liran Alon Reviewed-by: Nikita Leshenko Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Paolo Bonzini Reviewed-by: Wanpeng Li Signed-off-by: Radim Krčmář Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 9 ++++++++- arch/x86/kvm/vmx.c | 9 ++++----- 2 files changed, 12 insertions(+), 6 deletions(-) --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -362,6 +362,7 @@ static void recalc_intercepts(struct vcp { struct vmcb_control_area *c, *h; struct nested_state *g; + u32 h_intercept_exceptions; mark_dirty(svm->vmcb, VMCB_INTERCEPTS); @@ -372,9 +373,14 @@ static void recalc_intercepts(struct vcp h = &svm->nested.hsave->control; g = &svm->nested; + /* No need to intercept #UD if L1 doesn't intercept it */ + h_intercept_exceptions = + h->intercept_exceptions & ~(1U << UD_VECTOR); + c->intercept_cr = h->intercept_cr | g->intercept_cr; c->intercept_dr = h->intercept_dr | g->intercept_dr; - c->intercept_exceptions = h->intercept_exceptions | g->intercept_exceptions; + c->intercept_exceptions = + h_intercept_exceptions | g->intercept_exceptions; c->intercept = h->intercept | g->intercept; } @@ -2189,6 +2195,7 @@ static int ud_interception(struct vcpu_s { int er; + WARN_ON_ONCE(is_guest_mode(&svm->vcpu)); er = emulate_instruction(&svm->vcpu, EMULTYPE_TRAP_UD); if (er == EMULATE_USER_EXIT) return 0; --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1891,7 +1891,7 @@ static void update_exception_bitmap(stru { u32 eb; - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) | + eb = (1u << PF_VECTOR) | (1u << MC_VECTOR) | (1u << DB_VECTOR) | (1u << AC_VECTOR); if ((vcpu->guest_debug & (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) == @@ -1909,6 +1909,8 @@ static void update_exception_bitmap(stru */ if (is_guest_mode(vcpu)) eb |= get_vmcs12(vcpu)->exception_bitmap; + else + eb |= 1u << UD_VECTOR; vmcs_write32(EXCEPTION_BITMAP, eb); } @@ -5919,10 +5921,7 @@ static int handle_exception(struct kvm_v return 1; /* already handled by vmx_vcpu_run() */ if (is_invalid_opcode(intr_info)) { - if (is_guest_mode(vcpu)) { - kvm_queue_exception(vcpu, UD_VECTOR); - return 1; - } + WARN_ON_ONCE(is_guest_mode(vcpu)); er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD); if (er == EMULATE_USER_EXIT) return 0;