From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36193) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQNeh-0005tM-Sg for qemu-devel@nongnu.org; Wed, 19 Mar 2014 17:04:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WQNeZ-0004PN-7T for qemu-devel@nongnu.org; Wed, 19 Mar 2014 17:04:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60498) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQNeZ-0004P3-05 for qemu-devel@nongnu.org; Wed, 19 Mar 2014 17:03:59 -0400 Date: Wed, 19 Mar 2014 17:03:53 -0400 From: Luiz Capitulino Message-ID: <20140319170353.4428b501@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH v2 for-2.0] target-i386: x86_cpu_get_phys_page_debug(): support 1GB page translation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel Cc: peter.maydell@linaro.org, pbonzini@redhat.com, afaerber@suse.de, jan.kiszka@siemens.com Linux guests, when using more than 4GB of RAM, may end up using 1GB pages to store (kernel) data. When this happens, we're unable to debug a running Linux kernel with GDB: (gdb) p node_data[0]->node_id Cannot access memory at address 0xffff88013fffd3a0 (gdb) GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support translating 1GB pages in IA-32e paging mode and returns an error to GDB. This commit adds support for 1GB page translation for IA32e paging. Signed-off-by: Luiz capitulino --- - I'm proposing this patch for 2.0 because GDB debugging of large Linux guests is kind of broken - Changelog v2: - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block - Update changelog target-i386/helper.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/target-i386/helper.c b/target-i386/helper.c index 4f447b8..7cee501 100644 --- a/target-i386/helper.c +++ b/target-i386/helper.c @@ -941,6 +941,14 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) pdpe = ldq_phys(cs->as, pdpe_addr); if (!(pdpe & PG_PRESENT_MASK)) return -1; + + if (pdpe & PG_PSE_MASK) { + page_size = 1024 * 1024 * 1024; + pte = pdpe & ~( (page_size - 1) & ~0xfff); + pte &= ~(PG_NX_MASK | PG_HI_USER_MASK); + goto out; + } + } else #endif { @@ -993,6 +1001,7 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) pte = pte & env->a20_mask; } +out: page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); paddr = (pte & TARGET_PAGE_MASK) + page_offset; return paddr; -- 1.8.3.1