From patchwork Wed Dec 21 18:29:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Piggin X-Patchwork-Id: 707924 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tkNdy0qXkz9sfH for ; Thu, 22 Dec 2016 05:36:22 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="uwVmAK+z"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3tkNdx6s3zzDwZx for ; Thu, 22 Dec 2016 05:36:21 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="uwVmAK+z"; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mail-pg0-x241.google.com (mail-pg0-x241.google.com [IPv6:2607:f8b0:400e:c05::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3tkNVc1Y1YzDwKv for ; Thu, 22 Dec 2016 05:30:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="uwVmAK+z"; dkim-atps=neutral Received: by mail-pg0-x241.google.com with SMTP id w68so11149279pgw.3 for ; Wed, 21 Dec 2016 10:30:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=FuTWVUktpxn5OzZ34FMsPvh9T9jR85G2vpslrePI+gY=; b=uwVmAK+z0dfyisKuZ5e47q3NxnMxvsgneGQv3+YXapXOGW4/4ro2lAM/jw7QdzxxLI EWFadXawKD1mYZ2UZdyLB0ClZXCY9hrSHksQW/yYkcUsqkgIwhVsABln5jGo0Bjmlgox SmlAzhQ+6PIEm4NPCC5MB5cSLor/Fsp3H3lMafYLVb8PVFO0/hRP0X5+v9VunAde7GQK 8f65LunC7J9IObT0yW/1WD0liaFU7vkoguDtmt45b4mxmlrRJqQFKJU/vLlPKlQO6K2t YxM2QB/SEHRuw3n6v8KzyHH7TfepaUfM3qg1jUWJeEJDNNnOOqZSL+aRiJji8+MGkosN R3xg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=FuTWVUktpxn5OzZ34FMsPvh9T9jR85G2vpslrePI+gY=; b=TaFuDvCTvcx5ONqdH2UmGZMVnyCME0Q6nSAXvl3s0aZ/Q4LddubT+sa6s0O43nZ9Jw K1LpLTQOJhMo0VsrEiZtjpAWaXBeMvchUPnWZvQgpgxkMhnkb+gFTz53tr8mFMDDoPGw QvwCSPKItK/IPtglyvHyijvRQyPEVRZnaI58BlqToS+dWnKQJnctS9CApdUwU0Quy4HQ VG75rHVTK+BZt/5It9/7zlzHTxloKVq4Hv/Ls25F04G55A2uFCPyQb/SyBTY/HZBs65d yq6IWGenIlpO1XB4zGcmnj3A6qO40u7NbWws02IAy1U//VDve7IoYKavGT9Fb2Y1nedy 4Z+w== X-Gm-Message-State: AIkVDXLqo0ChjQDwd5XBRKA2qSxV/xSq4NnZxHtTSU7MgDnrC5MDZJ5sRF87iISpbm2PSg== X-Received: by 10.84.143.162 with SMTP id 31mr11365040plz.2.1482344998571; Wed, 21 Dec 2016 10:29:58 -0800 (PST) Received: from roar.au.ibm.com ([61.68.124.232]) by smtp.gmail.com with ESMTPSA id s17sm155660pgo.26.2016.12.21.10.29.55 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Dec 2016 10:29:58 -0800 (PST) From: Nicholas Piggin To: Paul Mackerras Subject: [PATCH 3/3] KVM: PPC: Book3S: 64-bit CONFIG_RELOCATABLE support for interrupts Date: Thu, 22 Dec 2016 04:29:27 +1000 Message-Id: <20161221182927.24562-4-npiggin@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20161221182927.24562-1-npiggin@gmail.com> References: <20161221182927.24562-1-npiggin@gmail.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Alexander Graf , Nicholas Piggin Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 64-bit Book3S exception handlers must find the dynamic kernel base to add to the target address when branching beyond __end_interrupts, in order to support kernel running at non-0 physical address. Support this in KVM by branching with CTR, similarly to regular interrupt handlers. The guest CTR saved in HSTATE_SCRATCH1 and restored after the branch. Without this, the host kernel hangs and crashes randomly when it is running at a non-0 address and a KVM guest is started. Signed-off-by: Nicholas Piggin Acked-by: Paul Mackerras --- arch/powerpc/include/asm/exception-64s.h | 43 +++++++++++++++++++++++++++++--- arch/powerpc/kernel/exceptions-64s.S | 4 +-- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 +++++--- arch/powerpc/kvm/book3s_segment.S | 7 ++++++ 4 files changed, 56 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index a02a268bde6b..e36c741e22d5 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -97,6 +97,11 @@ ld reg,PACAKBASE(r13); \ ori reg,reg,(ABS_ADDR(label))@l; +#define __LOAD_FAR_HANDLER(reg, label) \ + ld reg,PACAKBASE(r13); \ + ori reg,reg,(ABS_ADDR(label))@l; \ + addis reg,reg,(ABS_ADDR(label))@h; + /* Exception register prefixes */ #define EXC_HV H #define EXC_STD @@ -227,12 +232,44 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) mtctr reg; \ bctr +/* + * KVM requires >64K branches when branching from unrelocated code. + */ +#define __BRANCH_TO_KVM_EXIT(area, label) \ + mfctr r9; \ + std r9,HSTATE_SCRATCH1(r13); \ + __LOAD_FAR_HANDLER(r9, label); \ + mtctr r9; \ + ld r9,area+EX_R9(r13); \ + bctr + +#define BRANCH_TO_KVM(reg, label) \ + __LOAD_FAR_HANDLER(reg, label); \ + mtctr reg; \ + bctr + +#define BRANCH_LINK_TO_KVM(reg, label) \ + __LOAD_FAR_HANDLER(reg, label); \ + mtctr reg; \ + bctrl + #else #define BRANCH_TO_COMMON(reg, label) \ b label +#define BRANCH_TO_KVM(reg, label) \ + b label + +#define __BRANCH_TO_KVM_EXIT(area, label) \ + ld r9,area+EX_R9(r13); \ + b label + +#define BRANCH_LINK_TO_KVM(reg, label) \ + bl label + #endif + #define __KVM_HANDLER(area, h, n) \ BEGIN_FTR_SECTION_NESTED(947) \ ld r10,area+EX_CFAR(r13); \ @@ -246,8 +283,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) std r12,HSTATE_SCRATCH0(r13); \ sldi r12,r9,32; \ ori r12,r12,(n); \ - ld r9,area+EX_R9(r13); \ - b kvmppc_interrupt + __BRANCH_TO_KVM_EXIT(area, kvmppc_interrupt) #define __KVM_HANDLER_SKIP(area, h, n) \ cmpwi r10,KVM_GUEST_MODE_SKIP; \ @@ -260,8 +296,7 @@ END_FTR_SECTION_NESTED(ftr,ftr,943) std r12,HSTATE_SCRATCH0(r13); \ sldi r12,r9,32; \ ori r12,r12,(n); \ - ld r9,area+EX_R9(r13); \ - b kvmppc_interrupt; \ + __BRANCH_TO_KVM_EXIT(area, kvmppc_interrupt); \ 89: mtocrf 0x80,r9; \ ld r9,area+EX_R9(r13); \ ld r10,area+EX_R10(r13); \ diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 89b4f122aec6..d40307cfeb39 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -142,7 +142,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) lbz r0,HSTATE_HWTHREAD_REQ(r13) cmpwi r0,0 beq 1f - b kvm_start_guest + BRANCH_TO_KVM(r10, kvm_start_guest) 1: #endif @@ -977,7 +977,7 @@ TRAMP_REAL_BEGIN(hmi_exception_early) EXCEPTION_PROLOG_COMMON_2(PACA_EXGEN) EXCEPTION_PROLOG_COMMON_3(0xe60) addi r3,r1,STACK_FRAME_OVERHEAD - bl hmi_exception_realmode + BRANCH_LINK_TO_KVM(r4, hmi_exception_realmode) /* Windup the stack. */ /* Move original HSRR0 and HSRR1 into the respective regs */ ld r9,_MSR(r1) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 11882aac8216..c18ce740452b 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1060,15 +1060,16 @@ kvmppc_interrupt_hv: * R12 = (guest CR << 32) | interrupt vector * R13 = PACA * guest R12 saved in shadow VCPU SCRATCH0 + * guest CTR saved in shadow VCPU SCRATCH1 if RELOCATABLE * guest R13 saved in SPRN_SCRATCH0 */ - std r9, HSTATE_SCRATCH1(r13) + std r9, HSTATE_SCRATCH2(r13) lbz r9, HSTATE_IN_GUEST(r13) cmpwi r9, KVM_GUEST_MODE_HOST_HV beq kvmppc_bad_host_intr #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE cmpwi r9, KVM_GUEST_MODE_GUEST - ld r9, HSTATE_SCRATCH1(r13) + ld r9, HSTATE_SCRATCH2(r13) beq kvmppc_interrupt_pr #endif /* We're now back in the host but in guest MMU context */ @@ -1088,7 +1089,7 @@ kvmppc_interrupt_hv: std r6, VCPU_GPR(R6)(r9) std r7, VCPU_GPR(R7)(r9) std r8, VCPU_GPR(R8)(r9) - ld r0, HSTATE_SCRATCH1(r13) + ld r0, HSTATE_SCRATCH2(r13) std r0, VCPU_GPR(R9)(r9) std r10, VCPU_GPR(R10)(r9) std r11, VCPU_GPR(R11)(r9) @@ -1151,7 +1152,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) 11: stw r3,VCPU_HEIR(r9) /* these are volatile across C function calls */ +#ifdef CONFIG_RELOCATABLE + ld r3, HSTATE_SCRATCH1(r13) +#else mfctr r3 +#endif mfxer r4 std r3, VCPU_CTR(r9) std r4, VCPU_XER(r9) diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S index 68e45080cf93..2a2b96d53999 100644 --- a/arch/powerpc/kvm/book3s_segment.S +++ b/arch/powerpc/kvm/book3s_segment.S @@ -175,9 +175,16 @@ kvmppc_interrupt_pr: * R12 = (guest CR << 32) | exit handler id * R13 = PACA * HSTATE.SCRATCH0 = guest R12 + * HSTATE.SCRATCH1 = guest CTR if RELOCATABLE */ #ifdef CONFIG_PPC64 /* Match 32-bit entry */ +#ifdef CONFIG_RELOCATABLE + std r9, HSTATE_SCRATCH2(r13) + ld r9, HSTATE_SCRATCH1(r13) + mtctr r9 + ld r9, HSTATE_SCRATCH2(r13) +#endif rotldi r12, r12, 32 /* Flip R12 halves for stw */ stw r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */ srdi r12, r12, 32 /* shift trap into low half */