From patchwork Wed May 29 08:27:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: jordan.l.justen@intel.com X-Patchwork-Id: 247171 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 6E38C2C00AA for ; Wed, 29 May 2013 18:29:42 +1000 (EST) Received: from localhost ([::1]:42953 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UhblM-00066B-DY for incoming@patchwork.ozlabs.org; Wed, 29 May 2013 04:29:40 -0400 Received: from eggs.gnu.org ([208.118.235.92]:57801) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Uhbja-0003WJ-2T for qemu-devel@nongnu.org; Wed, 29 May 2013 04:27:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UhbjO-0005oc-3c for qemu-devel@nongnu.org; Wed, 29 May 2013 04:27:49 -0400 Received: from mga02.intel.com ([134.134.136.20]:39267) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UhbjN-0005oD-R8 for qemu-devel@nongnu.org; Wed, 29 May 2013 04:27:38 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 29 May 2013 01:27:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,763,1363158000"; d="scan'208";a="321205043" Received: from unknown (HELO jljusten-ivy.amr.corp.intel.com) ([10.255.13.121]) by orsmga001.jf.intel.com with ESMTP; 29 May 2013 01:27:36 -0700 From: Jordan Justen To: qemu-devel@nongnu.org Date: Wed, 29 May 2013 01:27:26 -0700 Message-Id: <1369816047-16384-4-git-send-email-jordan.l.justen@intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1369816047-16384-1-git-send-email-jordan.l.justen@intel.com> References: <1369816047-16384-1-git-send-email-jordan.l.justen@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.20 Cc: Jordan Justen Subject: [Qemu-devel] [PATCH v7 3/4] kvm: support using KVM_MEM_READONLY flag for regions 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org For readonly memory regions and rom devices in romd_mode, we make use of the KVM_MEM_READONLY. A slot that uses KVM_MEM_READONLY can be read from and code can execute from the region, but writes will exit to qemu. For rom devices with !romd_mode, we force the slot to be removed so reads or writes to the region will exit to qemu. (Note that a memory region in this state is not executable within kvm.) v7: * Update for readable => romd_mode rename (5f9a5ea1) Signed-off-by: Jordan Justen Reviewed-by: Xiao Guangrong (v4) Reviewed-by: Paolo Bonzini (v5) --- kvm-all.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 327ae12..8e7bbf8 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -201,12 +201,18 @@ static int kvm_set_user_memory_region(KVMState *s, KVMSlot *slot) mem.slot = slot->slot; mem.guest_phys_addr = slot->start_addr; - mem.memory_size = slot->memory_size; mem.userspace_addr = (unsigned long)slot->ram; mem.flags = slot->flags; if (s->migration_log) { mem.flags |= KVM_MEM_LOG_DIRTY_PAGES; } + if (mem.flags & KVM_MEM_READONLY) { + /* Set the slot size to 0 before setting the slot to the desired + * value. This is needed based on KVM commit 75d61fbc. */ + mem.memory_size = 0; + kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem); + } + mem.memory_size = slot->memory_size; return kvm_vm_ioctl(s, KVM_SET_USER_MEMORY_REGION, &mem); } @@ -268,9 +274,14 @@ err: * dirty pages logging control */ -static int kvm_mem_flags(KVMState *s, bool log_dirty) +static int kvm_mem_flags(KVMState *s, bool log_dirty, bool readonly) { - return log_dirty ? KVM_MEM_LOG_DIRTY_PAGES : 0; + int flags = 0; + flags = log_dirty ? KVM_MEM_LOG_DIRTY_PAGES : 0; + if (readonly && kvm_readonly_mem_allowed) { + flags |= KVM_MEM_READONLY; + } + return flags; } static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty) @@ -281,7 +292,7 @@ static int kvm_slot_dirty_pages_log_change(KVMSlot *mem, bool log_dirty) old_flags = mem->flags; - flags = (mem->flags & ~mask) | kvm_mem_flags(s, log_dirty); + flags = (mem->flags & ~mask) | kvm_mem_flags(s, log_dirty, false); mem->flags = flags; /* If nothing changed effectively, no need to issue ioctl */ @@ -619,6 +630,8 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) int err; MemoryRegion *mr = section->mr; bool log_dirty = memory_region_is_logging(mr); + bool writeable = !mr->readonly && !mr->rom_device; + bool readonly_flag = mr->readonly || memory_region_is_romd(mr); hwaddr start_addr = section->offset_within_address_space; ram_addr_t size = section->size; void *ram = NULL; @@ -638,7 +651,13 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) } if (!memory_region_is_ram(mr)) { - return; + if (writeable || !kvm_readonly_mem_allowed) { + return; + } else if (!mr->romd_mode) { + /* If the memory device is not in romd_mode, then we actually want + * to remove the kvm memory slot so all accesses will trap. */ + add = false; + } } ram = memory_region_get_ram_ptr(mr) + section->offset_within_region + delta; @@ -687,7 +706,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) mem->memory_size = old.memory_size; mem->start_addr = old.start_addr; mem->ram = old.ram; - mem->flags = kvm_mem_flags(s, log_dirty); + mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -708,7 +727,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) mem->memory_size = start_addr - old.start_addr; mem->start_addr = old.start_addr; mem->ram = old.ram; - mem->flags = kvm_mem_flags(s, log_dirty); + mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -732,7 +751,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) size_delta = mem->start_addr - old.start_addr; mem->memory_size = old.memory_size - size_delta; mem->ram = old.ram + size_delta; - mem->flags = kvm_mem_flags(s, log_dirty); + mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag); err = kvm_set_user_memory_region(s, mem); if (err) { @@ -754,7 +773,7 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add) mem->memory_size = size; mem->start_addr = start_addr; mem->ram = ram; - mem->flags = kvm_mem_flags(s, log_dirty); + mem->flags = kvm_mem_flags(s, log_dirty, readonly_flag); err = kvm_set_user_memory_region(s, mem); if (err) {