From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A30B0C2D0E0 for ; Tue, 15 Sep 2020 10:47:17 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 3670920B1F for ; Tue, 15 Sep 2020 10:47:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="YpC3+yp3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3670920B1F Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D74454B339; Tue, 15 Sep 2020 06:47:16 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@google.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id GXrGTnUKmfMF; Tue, 15 Sep 2020 06:47:15 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7872F4B379; Tue, 15 Sep 2020 06:47:14 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 8068A4B319 for ; Tue, 15 Sep 2020 06:47:13 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ysFjQDaU7RQA for ; Tue, 15 Sep 2020 06:47:12 -0400 (EDT) Received: from mail-ej1-f73.google.com (mail-ej1-f73.google.com [209.85.218.73]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 3A6434B24D for ; Tue, 15 Sep 2020 06:47:12 -0400 (EDT) Received: by mail-ej1-f73.google.com with SMTP id li24so1110492ejb.6 for ; Tue, 15 Sep 2020 03:47:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=FjAmdHcCy7ece6Sz4HjhZ6GffgSinMrmw6yNTCSVSwk=; b=YpC3+yp3l42Z4Sm6R2LtFYp/XF3jtinmX30Icv9tAiSGyRXQI82CrxSO4GnB0m4h77 iVTmqzL6Xn86AdrHIWRElBRH89gbOH08FvqgeMBpTTQBq6NRI2HsK00txvmpg1MhU6dv Hmjg5+6YGxEVXkQ3s5f/d4QVWRhvZ3/CeV6EPBPQAlRD+bm8rcEXsuzBv4JAgk47gKYr /p8v8NgQkklQolSo4nYKyy9/e+UXsUL2+m7uqAtKeVPvQjg86EeGmk0w6hatlV+NvRNR YfRXTI2+HMGEUs5kyMwoDQA4qIfzwstEGsk21Fz2TF9EAIEwslxZB62kJWrnvs32XJ77 ACXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=FjAmdHcCy7ece6Sz4HjhZ6GffgSinMrmw6yNTCSVSwk=; b=r0AQA3kMPINO6bQBRa5w0Mw6XFvErOjRyBcKAbCSR44DuVUik0pbqcjEh7HUcizGu6 dnli/MkZqh7swKHe1flHNNrOJe7AJg4qChLKX2W9yt+5OIlu254RI5wX9809Krc8trd9 fMfgCb6b5+H2p/zVrdTRbY1MdmLXO9EVvQjzVxJ/Ir1yhCCIH0t29rV9ALmHEGgNvcf8 rEFqtNag12tEJmMboLFbc+mjnLn6GpdLbuJy+LifvZvA11D2xgrtQ7DuvJ0pwj6j+cWV npUAd+ywSx1UNV1shjWb5yIfU/T71OqOYHAKUKEjzGeraZf4rsafYYokF9BwhGOq0nEx DtEg== X-Gm-Message-State: AOAM532kTDe4m18TdmlGnxK0bEyXfCCcJyKObrXsHoz1/F4VDHigEIbW ER3RgQFvSkx4w5X5+U1IiC3STVv/WpTD8ohHBUxIXt1N+Mzk9m1JgPC4b4C8FkaAxSvNrKaMI4l MzxCwsTGjFxFwGhO032FqEW3bj9DWfcpkBafPRkvN3w7GrrcMGgUAe1KvCSUV7JDFSvJQEw== X-Google-Smtp-Source: ABdhPJxwgpm6jAly1zznwB2mChxPFf5CLS+C4Xqq/ymMDVdI5vF/UmDay3loY8j87L7qnbdGz7bkSvNWSyE= X-Received: from ascull.lon.corp.google.com ([2a00:79e0:d:109:4a0f:cfff:fe4a:6363]) (user=ascull job=sendgmr) by 2002:a17:906:edca:: with SMTP id sb10mr18951191ejb.60.1600166830976; Tue, 15 Sep 2020 03:47:10 -0700 (PDT) Date: Tue, 15 Sep 2020 11:46:34 +0100 In-Reply-To: <20200915104643.2543892-1-ascull@google.com> Message-Id: <20200915104643.2543892-11-ascull@google.com> Mime-Version: 1.0 References: <20200915104643.2543892-1-ascull@google.com> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog Subject: [PATCH v4 10/19] KVM: arm64: Restore hyp when panicking in guest context From: Andrew Scull To: kvmarm@lists.cs.columbia.edu Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com, maz@kernel.org, Sudeep Holla , catalin.marinas@arm.com, will@kernel.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu If the guest context is loaded when a panic is triggered, restore the hyp context so e.g. the shadow call stack works when hyp_panic() is called and SP_EL0 is valid when the host's panic() is called. Use the hyp context's __hyp_running_vcpu field to track when hyp transitions to and from the guest vcpu so the exception handlers know whether the context needs to be restored. Signed-off-by: Andrew Scull --- arch/arm64/include/asm/kvm_asm.h | 10 ++++++++++ arch/arm64/kvm/hyp/entry.S | 24 ++++++++++++++++++++++++ arch/arm64/kvm/hyp/hyp-entry.S | 5 ++--- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 +++- arch/arm64/kvm/hyp/nvhe/host.S | 5 +++++ 5 files changed, 44 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index fe51c06d480d..4df2bd8882bc 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -236,6 +236,16 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] .endm +.macro get_loaded_vcpu vcpu, ctxt + hyp_adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu + ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + +.macro set_loaded_vcpu vcpu, ctxt, tmp + hyp_adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp + str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + /* * KVM extable for unexpected exceptions. * In the same format _asm_extable, but output to a different section so that diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 38cca690a6ff..4787fc82790c 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -86,6 +86,8 @@ alternative_else_nop_endif ret 1: + set_loaded_vcpu x0, x1, x2 + add x29, x0, #VCPU_CONTEXT // Macro ptrauth_switch_to_guest format: @@ -116,6 +118,26 @@ alternative_else_nop_endif eret sb +SYM_INNER_LABEL(__guest_exit_panic, SYM_L_GLOBAL) + // x2-x29,lr: vcpu regs + // vcpu x0-x1 on the stack + + // If the hyp context is loaded, go straight to hyp_panic + get_loaded_vcpu x0, x1 + cbz x0, hyp_panic + + // The hyp context is saved so make sure it is restored to allow + // hyp_panic to run at hyp and, subsequently, panic to run in the host. + // This makes use of __guest_exit to avoid duplication but sets the + // return address to tail call into hyp_panic. As a side effect, the + // current state is saved to the guest context but it will only be + // accurate if the guest had been completely restored. + hyp_adr_this_cpu x0, kvm_hyp_ctxt, x1 + adr x1, hyp_panic + str x1, [x0, #CPU_XREG_OFFSET(30)] + + get_vcpu_ptr x1, x0 + SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) // x0: return code // x1: vcpu @@ -163,6 +185,8 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) // Now restore the hyp regs restore_callee_saved_regs x2 + set_loaded_vcpu xzr, x1, x2 + alternative_if ARM64_HAS_RAS_EXTN // If we have the RAS extensions we can consume a pending error // without an unmask-SError and isb. The ESB-instruction consumed any diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index f92489250dfc..bc9f53df46f5 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -145,7 +145,7 @@ el2_error: eret sb -.macro invalid_vector label, target = hyp_panic +.macro invalid_vector label, target = __guest_exit_panic .align 2 SYM_CODE_START(\label) b \target @@ -186,10 +186,9 @@ check_preamble_length 661b, 662b .macro invalid_vect target .align 7 661: - b \target nop + stp x0, x1, [sp, #-16]! 662: - ldp x0, x1, [sp], #16 b \target check_preamble_length 661b, 662b diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index afe714056b97..821721b78ad9 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -509,6 +509,7 @@ static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu) static inline void __kvm_unexpected_el2_exception(void) { + extern char __guest_exit_panic[]; unsigned long addr, fixup; struct exception_table_entry *entry, *end; unsigned long elr_el2 = read_sysreg(elr_el2); @@ -529,7 +530,8 @@ static inline void __kvm_unexpected_el2_exception(void) return; } - hyp_panic(); + /* Trigger a panic after restoring the hyp context. */ + write_sysreg(__guest_exit_panic, elr_el2); } #endif /* __ARM64_KVM_HYP_SWITCH_H__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index da21fddcef75..9ab7814e6114 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -75,6 +75,11 @@ SYM_FUNC_END(__hyp_do_panic) .macro invalid_host_vect .align 7 + /* If a guest is loaded, panic out of it. */ + stp x0, x1, [sp, #-16]! + get_loaded_vcpu x0, x1 + cbnz x0, __guest_exit_panic + add sp, sp, #16 b hyp_panic .endm -- 2.28.0.618.gf4bc123cb7-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9A32C43461 for ; Tue, 15 Sep 2020 11:02:12 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8072C21D24 for ; Tue, 15 Sep 2020 11:02:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OMDwbcuU"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="YpC3+yp3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8072C21D24 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:From:Subject:References:Mime-Version:Message-Id: In-Reply-To:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=SqI21kUG6FBb+xP11ipkQhwwDV4LmTZBlLmJHpXbaqw=; b=OMDwbcuURSdpZ9gCDrY9IE6le o2GOpcXeVDbvrQjqj1B7j2rJ3PtPkeKQIRw825jRHy7xPnWx828hDpJGpuzs39+UdPwrktQD5S7KB W12FFhbTxevOQTOujhkyaDUoFIP1Lj2hEKHnSaM+xHrOpDNTtCQ6dzCYfoHVJIPcnzkpKsdMxOFTf KpioWEUvPyT2ztfN+cZbtQAnwsryfNJhVV0liYDMw0vX2cu8TTVlM5S+FyUwOYKCOP5v4ynsH3sER tfJaqDnXgLk61d4l7zTi8Xs8U93XxZJw2OgwOwqjJN4GW+24BPJMe4cAdj8wpKCQ1LSL+cY7XJzjS 9y1J04RQA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kI8g4-0005xq-Oq; Tue, 15 Sep 2020 10:59:13 +0000 Received: from mail-ej1-x64a.google.com ([2a00:1450:4864:20::64a]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kI8UW-0000uO-6u for linux-arm-kernel@lists.infradead.org; Tue, 15 Sep 2020 10:47:18 +0000 Received: by mail-ej1-x64a.google.com with SMTP id m24so1089662ejx.22 for ; Tue, 15 Sep 2020 03:47:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=FjAmdHcCy7ece6Sz4HjhZ6GffgSinMrmw6yNTCSVSwk=; b=YpC3+yp3l42Z4Sm6R2LtFYp/XF3jtinmX30Icv9tAiSGyRXQI82CrxSO4GnB0m4h77 iVTmqzL6Xn86AdrHIWRElBRH89gbOH08FvqgeMBpTTQBq6NRI2HsK00txvmpg1MhU6dv Hmjg5+6YGxEVXkQ3s5f/d4QVWRhvZ3/CeV6EPBPQAlRD+bm8rcEXsuzBv4JAgk47gKYr /p8v8NgQkklQolSo4nYKyy9/e+UXsUL2+m7uqAtKeVPvQjg86EeGmk0w6hatlV+NvRNR YfRXTI2+HMGEUs5kyMwoDQA4qIfzwstEGsk21Fz2TF9EAIEwslxZB62kJWrnvs32XJ77 ACXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=FjAmdHcCy7ece6Sz4HjhZ6GffgSinMrmw6yNTCSVSwk=; b=JsnnNepQO6Kfy0LFi3h2Sth9SEKOtfqRFpsj6DIG7XI+nkvACQMgFIvhGAZT9leymB RSlYqxuEem4oI7YwFUY3X7GvRi2nS4OIxbd/9cVtjb0acljChMTpyWOelzDDBPEgi9kV nTj3lkZ1WDdIHftIsa9JNaANBngwNnNPoxJl06KF4ueuQyVYMOs3i1CWM2yVo2ejUkqP PLMuLToHWkrz9d9LjgwZ0D79SsflQB6Oc9CjDhzhwPw6vnHjdMX1qhcY4aiAhNbDUvDQ 298j2GLnhO5sL830lPN/MDnjNC24thLtyxgFk4DeUx2NshnU7aJZV3fUgKSf5p0e5Moi OejQ== X-Gm-Message-State: AOAM530SZm8jvZWkPLtBKoq99KT7YSl0zyQ6MBPMiienC1NTf0ESyo2u Fr6TFjTCkOeqT9HcvvGUJoPeNPyAqI0= X-Google-Smtp-Source: ABdhPJxwgpm6jAly1zznwB2mChxPFf5CLS+C4Xqq/ymMDVdI5vF/UmDay3loY8j87L7qnbdGz7bkSvNWSyE= X-Received: from ascull.lon.corp.google.com ([2a00:79e0:d:109:4a0f:cfff:fe4a:6363]) (user=ascull job=sendgmr) by 2002:a17:906:edca:: with SMTP id sb10mr18951191ejb.60.1600166830976; Tue, 15 Sep 2020 03:47:10 -0700 (PDT) Date: Tue, 15 Sep 2020 11:46:34 +0100 In-Reply-To: <20200915104643.2543892-1-ascull@google.com> Message-Id: <20200915104643.2543892-11-ascull@google.com> Mime-Version: 1.0 References: <20200915104643.2543892-1-ascull@google.com> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog Subject: [PATCH v4 10/19] KVM: arm64: Restore hyp when panicking in guest context From: Andrew Scull To: kvmarm@lists.cs.columbia.edu X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200915_064716_496381_83A3C758 X-CRM114-Status: GOOD ( 19.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arm-kernel@lists.infradead.org, kernel-team@android.com, suzuki.poulose@arm.com, maz@kernel.org, Sudeep Holla , james.morse@arm.com, Andrew Scull , catalin.marinas@arm.com, will@kernel.org, julien.thierry.kdev@gmail.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org If the guest context is loaded when a panic is triggered, restore the hyp context so e.g. the shadow call stack works when hyp_panic() is called and SP_EL0 is valid when the host's panic() is called. Use the hyp context's __hyp_running_vcpu field to track when hyp transitions to and from the guest vcpu so the exception handlers know whether the context needs to be restored. Signed-off-by: Andrew Scull --- arch/arm64/include/asm/kvm_asm.h | 10 ++++++++++ arch/arm64/kvm/hyp/entry.S | 24 ++++++++++++++++++++++++ arch/arm64/kvm/hyp/hyp-entry.S | 5 ++--- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 +++- arch/arm64/kvm/hyp/nvhe/host.S | 5 +++++ 5 files changed, 44 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index fe51c06d480d..4df2bd8882bc 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -236,6 +236,16 @@ extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] .endm +.macro get_loaded_vcpu vcpu, ctxt + hyp_adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu + ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + +.macro set_loaded_vcpu vcpu, ctxt, tmp + hyp_adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp + str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + /* * KVM extable for unexpected exceptions. * In the same format _asm_extable, but output to a different section so that diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index 38cca690a6ff..4787fc82790c 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -86,6 +86,8 @@ alternative_else_nop_endif ret 1: + set_loaded_vcpu x0, x1, x2 + add x29, x0, #VCPU_CONTEXT // Macro ptrauth_switch_to_guest format: @@ -116,6 +118,26 @@ alternative_else_nop_endif eret sb +SYM_INNER_LABEL(__guest_exit_panic, SYM_L_GLOBAL) + // x2-x29,lr: vcpu regs + // vcpu x0-x1 on the stack + + // If the hyp context is loaded, go straight to hyp_panic + get_loaded_vcpu x0, x1 + cbz x0, hyp_panic + + // The hyp context is saved so make sure it is restored to allow + // hyp_panic to run at hyp and, subsequently, panic to run in the host. + // This makes use of __guest_exit to avoid duplication but sets the + // return address to tail call into hyp_panic. As a side effect, the + // current state is saved to the guest context but it will only be + // accurate if the guest had been completely restored. + hyp_adr_this_cpu x0, kvm_hyp_ctxt, x1 + adr x1, hyp_panic + str x1, [x0, #CPU_XREG_OFFSET(30)] + + get_vcpu_ptr x1, x0 + SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) // x0: return code // x1: vcpu @@ -163,6 +185,8 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOBAL) // Now restore the hyp regs restore_callee_saved_regs x2 + set_loaded_vcpu xzr, x1, x2 + alternative_if ARM64_HAS_RAS_EXTN // If we have the RAS extensions we can consume a pending error // without an unmask-SError and isb. The ESB-instruction consumed any diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index f92489250dfc..bc9f53df46f5 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -145,7 +145,7 @@ el2_error: eret sb -.macro invalid_vector label, target = hyp_panic +.macro invalid_vector label, target = __guest_exit_panic .align 2 SYM_CODE_START(\label) b \target @@ -186,10 +186,9 @@ check_preamble_length 661b, 662b .macro invalid_vect target .align 7 661: - b \target nop + stp x0, x1, [sp, #-16]! 662: - ldp x0, x1, [sp], #16 b \target check_preamble_length 661b, 662b diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index afe714056b97..821721b78ad9 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -509,6 +509,7 @@ static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu) static inline void __kvm_unexpected_el2_exception(void) { + extern char __guest_exit_panic[]; unsigned long addr, fixup; struct exception_table_entry *entry, *end; unsigned long elr_el2 = read_sysreg(elr_el2); @@ -529,7 +530,8 @@ static inline void __kvm_unexpected_el2_exception(void) return; } - hyp_panic(); + /* Trigger a panic after restoring the hyp context. */ + write_sysreg(__guest_exit_panic, elr_el2); } #endif /* __ARM64_KVM_HYP_SWITCH_H__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index da21fddcef75..9ab7814e6114 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -75,6 +75,11 @@ SYM_FUNC_END(__hyp_do_panic) .macro invalid_host_vect .align 7 + /* If a guest is loaded, panic out of it. */ + stp x0, x1, [sp, #-16]! + get_loaded_vcpu x0, x1 + cbnz x0, __guest_exit_panic + add sp, sp, #16 b hyp_panic .endm -- 2.28.0.618.gf4bc123cb7-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel