From patchwork Wed Mar 16 05:07:00 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 8594901 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 19906C0553 for ; Wed, 16 Mar 2016 05:10:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1B735202F0 for ; Wed, 16 Mar 2016 05:10:09 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 14E5120295 for ; Wed, 16 Mar 2016 05:10:08 +0000 (UTC) Received: from localhost ([::1]:53179 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ag3ih-00010b-CN for patchwork-qemu-devel@patchwork.kernel.org; Wed, 16 Mar 2016 01:10:07 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34264) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ag3es-0001Ai-Gq for qemu-devel@nongnu.org; Wed, 16 Mar 2016 01:06:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ag3ep-0005Re-UR for qemu-devel@nongnu.org; Wed, 16 Mar 2016 01:06:10 -0400 Received: from ozlabs.org ([103.22.144.67]:41054) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ag3ep-0005Pf-8z; Wed, 16 Mar 2016 01:06:07 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 3qPzwB6zPwz9t5b; Wed, 16 Mar 2016 16:06:02 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1458104762; bh=TfoX/U+7qIQo254Kfi5fuLV0zofrke9iUAi7Na6WGLE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WDabssnST7NdooBrFCiKsMiG4cNAkI3IB3yqZtytSZr8VwROSVcK4c8OQ9JSPgIq/ XSxSvvvEdZzn7pc5e+7sP7hpcycCXkH67vMZVmsrGXp4QbPWru/5NoAigsPegbg8k9 9Cng86KbjLb0qD8GX16i7H/jrzlDx7dJkR5v6SRg= From: David Gibson To: peter.maydell@linaro.org Date: Wed, 16 Mar 2016 16:07:00 +1100 Message-Id: <1458104828-32541-9-git-send-email-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1458104828-32541-1-git-send-email-david@gibson.dropbear.id.au> References: <1458104828-32541-1-git-send-email-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 103.22.144.67 Cc: qemu-devel@nongnu.org, aik@ozlabs.ru, agraf@suse.de, mdroth@linux.vnet.ibm.com, alex.williamson@redhat.com, qemu-ppc@nongnu.org, David Gibson Subject: [Qemu-devel] [PULL 08/16] target-ppc: Eliminate kvmppc_kern_htab global X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP fa48b43 "target-ppc: Remove hack for ppc_hash64_load_hpte*() with HV KVM" purports to remove a hack in the handling of hash page tables (HPTs) managed by KVM instead of qemu. However, it actually went in the wrong direction. That patch requires anything looking for an external HPT (that is one not managed by the guest itself) to check both env->external_htab (for a qemu managed HPT) and kvmppc_kern_htab (for a KVM managed HPT). That's a problem because kvmppc_kern_htab is local to mmu-hash64.c, but some places which need to check for an external HPT are outside that, such as kvm_arch_get_registers(). The latter was subtly broken by the earlier patch such that gdbstub can no longer access memory. Basically a KVM managed HPT is much more like a qemu managed HPT than it is like a guest managed HPT, so the original "hack" was actually on the right track. This partially reverts fa48b43, so we again mark a KVM managed external HPT by putting a special but non-NULL value in env->external_htab. It then goes further, using that marker to eliminate the kvmppc_kern_htab global entirely. The ppc_hash64_set_external_hpt() helper function is extended to set that marker if passed a NULL value (if you're setting an external HPT, but don't have an actual HPT to set, the assumption is that it must be a KVM managed HPT). This also has some flow-on changes to the HPT access helpers, required by the above changes. Reported-by: Greg Kurz Signed-off-by: David Gibson Reviewed-by: Thomas Huth Reviewed-by: Greg Kurz Tested-by: Greg Kurz --- hw/ppc/spapr.c | 3 +-- hw/ppc/spapr_hcall.c | 10 +++++----- target-ppc/mmu-hash64.c | 40 ++++++++++++++++++---------------------- target-ppc/mmu-hash64.h | 9 +++------ 4 files changed, 27 insertions(+), 35 deletions(-) diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c index eb66a87..79a70a9 100644 --- a/hw/ppc/spapr.c +++ b/hw/ppc/spapr.c @@ -1091,7 +1091,7 @@ static void spapr_reallocate_hpt(sPAPRMachineState *spapr, int shift, } spapr->htab_shift = shift; - kvmppc_kern_htab = true; + spapr->htab = NULL; } else { /* kernel-side HPT not needed, allocate in userspace instead */ size_t size = 1ULL << shift; @@ -1106,7 +1106,6 @@ static void spapr_reallocate_hpt(sPAPRMachineState *spapr, int shift, memset(spapr->htab, 0, size); spapr->htab_shift = shift; - kvmppc_kern_htab = false; for (i = 0; i < size / HASH_PTE_SIZE_64; i++) { DIRTY_HPTE(HPTE(spapr->htab, i)); diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c index 1733482..b2b1b93 100644 --- a/hw/ppc/spapr_hcall.c +++ b/hw/ppc/spapr_hcall.c @@ -122,17 +122,17 @@ static target_ulong h_enter(PowerPCCPU *cpu, sPAPRMachineState *spapr, break; } } - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); if (index == 8) { return H_PTEG_FULL; } } else { token = ppc_hash64_start_access(cpu, pte_index); if (ppc_hash64_load_hpte0(cpu, token, 0) & HPTE64_V_VALID) { - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); return H_PTEG_FULL; } - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); } ppc_hash64_store_hpte(cpu, pte_index + index, @@ -165,7 +165,7 @@ static RemoveResult remove_hpte(PowerPCCPU *cpu, target_ulong ptex, token = ppc_hash64_start_access(cpu, ptex); v = ppc_hash64_load_hpte0(cpu, token, 0); r = ppc_hash64_load_hpte1(cpu, token, 0); - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); if ((v & HPTE64_V_VALID) == 0 || ((flags & H_AVPN) && (v & ~0x7fULL) != avpn) || @@ -288,7 +288,7 @@ static target_ulong h_protect(PowerPCCPU *cpu, sPAPRMachineState *spapr, token = ppc_hash64_start_access(cpu, pte_index); v = ppc_hash64_load_hpte0(cpu, token, 0); r = ppc_hash64_load_hpte1(cpu, token, 0); - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); if ((v & HPTE64_V_VALID) == 0 || ((flags & H_AVPN) && (v & ~0x7fULL) != avpn)) { diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c index 7b5200b..d175fda 100644 --- a/target-ppc/mmu-hash64.c +++ b/target-ppc/mmu-hash64.c @@ -36,10 +36,11 @@ #endif /* - * Used to indicate whether we have allocated htab in the - * host kernel + * Used to indicate that a CPU has its hash page table (HPT) managed + * within the host kernel */ -bool kvmppc_kern_htab; +#define MMU_HASH64_KVM_MANAGED_HPT ((void *)-1) + /* * SLB handling */ @@ -283,7 +284,11 @@ void ppc_hash64_set_external_hpt(PowerPCCPU *cpu, void *hpt, int shift, cpu_synchronize_state(CPU(cpu)); - env->external_htab = hpt; + if (hpt) { + env->external_htab = hpt; + } else { + env->external_htab = MMU_HASH64_KVM_MANAGED_HPT; + } ppc_hash64_set_sdr1(cpu, (target_ulong)(uintptr_t)hpt | (shift - 18), &local_err); if (local_err) { @@ -396,25 +401,16 @@ uint64_t ppc_hash64_start_access(PowerPCCPU *cpu, target_ulong pte_index) hwaddr pte_offset; pte_offset = pte_index * HASH_PTE_SIZE_64; - if (kvmppc_kern_htab) { + if (cpu->env.external_htab == MMU_HASH64_KVM_MANAGED_HPT) { /* * HTAB is controlled by KVM. Fetch the PTEG into a new buffer. */ token = kvmppc_hash64_read_pteg(cpu, pte_index); - if (token) { - return token; - } + } else if (cpu->env.external_htab) { /* - * pteg read failed, even though we have allocated htab via - * kvmppc_reset_htab. + * HTAB is controlled by QEMU. Just point to the internally + * accessible PTEG. */ - return 0; - } - /* - * HTAB is controlled by QEMU. Just point to the internally - * accessible PTEG. - */ - if (cpu->env.external_htab) { token = (uint64_t)(uintptr_t) cpu->env.external_htab + pte_offset; } else if (cpu->env.htab_base) { token = cpu->env.htab_base + pte_offset; @@ -422,9 +418,9 @@ uint64_t ppc_hash64_start_access(PowerPCCPU *cpu, target_ulong pte_index) return token; } -void ppc_hash64_stop_access(uint64_t token) +void ppc_hash64_stop_access(PowerPCCPU *cpu, uint64_t token) { - if (kvmppc_kern_htab) { + if (cpu->env.external_htab == MMU_HASH64_KVM_MANAGED_HPT) { kvmppc_hash64_free_pteg(token); } } @@ -453,11 +449,11 @@ static hwaddr ppc_hash64_pteg_search(PowerPCCPU *cpu, hwaddr hash, && HPTE64_V_COMPARE(pte0, ptem)) { pte->pte0 = pte0; pte->pte1 = pte1; - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); return (pte_index + i) * HASH_PTE_SIZE_64; } } - ppc_hash64_stop_access(token); + ppc_hash64_stop_access(cpu, token); /* * We didn't find a valid entry. */ @@ -772,7 +768,7 @@ void ppc_hash64_store_hpte(PowerPCCPU *cpu, { CPUPPCState *env = &cpu->env; - if (kvmppc_kern_htab) { + if (env->external_htab == MMU_HASH64_KVM_MANAGED_HPT) { kvmppc_hash64_write_pte(env, pte_index, pte0, pte1); return; } diff --git a/target-ppc/mmu-hash64.h b/target-ppc/mmu-hash64.h index 138cd7e..9bf8b9b 100644 --- a/target-ppc/mmu-hash64.h +++ b/target-ppc/mmu-hash64.h @@ -90,16 +90,13 @@ unsigned ppc_hash64_hpte_page_shift_noslb(PowerPCCPU *cpu, #define HPTE64_V_1TB_SEG 0x4000000000000000ULL #define HPTE64_V_VRMA_MASK 0x4001ffffff000000ULL - -extern bool kvmppc_kern_htab; - void ppc_hash64_set_sdr1(PowerPCCPU *cpu, target_ulong value, Error **errp); void ppc_hash64_set_external_hpt(PowerPCCPU *cpu, void *hpt, int shift, Error **errp); uint64_t ppc_hash64_start_access(PowerPCCPU *cpu, target_ulong pte_index); -void ppc_hash64_stop_access(uint64_t token); +void ppc_hash64_stop_access(PowerPCCPU *cpu, uint64_t token); static inline target_ulong ppc_hash64_load_hpte0(PowerPCCPU *cpu, uint64_t token, int index) @@ -108,7 +105,7 @@ static inline target_ulong ppc_hash64_load_hpte0(PowerPCCPU *cpu, uint64_t addr; addr = token + (index * HASH_PTE_SIZE_64); - if (kvmppc_kern_htab || env->external_htab) { + if (env->external_htab) { return ldq_p((const void *)(uintptr_t)addr); } else { return ldq_phys(CPU(cpu)->as, addr); @@ -122,7 +119,7 @@ static inline target_ulong ppc_hash64_load_hpte1(PowerPCCPU *cpu, uint64_t addr; addr = token + (index * HASH_PTE_SIZE_64) + HASH_PTE_SIZE_64/2; - if (kvmppc_kern_htab || env->external_htab) { + if (env->external_htab) { return ldq_p((const void *)(uintptr_t)addr); } else { return ldq_phys(CPU(cpu)->as, addr);