From c8c14bcb72e436fb4aff99b4b2b92e44f2e715b5 Mon Sep 17 00:00:00 2001 From: Luiz Capitulino Date: Wed, 19 Mar 2014 17:03:53 -0400 Subject: [PATCH 1/2] target-i386: x86_cpu_get_phys_page_debug(): support 1GB page translation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Paolo Bonzini Reviewed-by: Jan Kiszka Signed-off-by: Andreas Färber --- target-i386/helper.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/target-i386/helper.c b/target-i386/helper.c index 4f447b8cf9..372f0e3ecb 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 +1001,9 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr) pte = pte & env->a20_mask; } +#ifdef TARGET_X86_64 +out: +#endif page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); paddr = (pte & TARGET_PAGE_MASK) + page_offset; return paddr; From 0d6d1ab4990b6e8c6f24e9b1308801d657d411ad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andreas=20F=C3=A4rber?= Date: Fri, 28 Mar 2014 16:25:07 +0100 Subject: [PATCH 2/2] cpu: Avoid QOM casts for CPU() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CPU address spaces touching load and store helpers as well as the movement of (almost) all fields from CPU_COMMON to CPUState have led to a noticeable increase of CPU() usage in "hot" paths for both TCG and KVM. While CPU()'s OBJECT_CHECK() might help detect development errors, i.e. in form of crashes due to QOM vs. non-QOM mismatches rather than QOM type mismatches, it is not really needed at runtime since mostly used in CPU-specific paths, coming from a target-specific CPU subtype. If that pointer is damaged, other errors are highly likely to occur elsewhere anyway. Keep the CPU() macro for a consistent developer experience and for flexibility to exchange its implementation, but turn it into a pure, unchecked C cast for now. Compare commit 6e42be7cd10260fd3a006d94f6c870692bf7a2c0. Reported-by: Laurent Desnogues Suggested-by: Paolo Bonzini Signed-off-by: Andreas Färber --- include/qom/cpu.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/include/qom/cpu.h b/include/qom/cpu.h index f99885a137..df977c88f0 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -53,7 +53,12 @@ typedef uint64_t vaddr; #define TYPE_CPU "cpu" -#define CPU(obj) OBJECT_CHECK(CPUState, (obj), TYPE_CPU) +/* Since this macro is used a lot in hot code paths and in conjunction with + * FooCPU *foo_env_get_cpu(), we deviate from usual QOM practice by using + * an unchecked cast. + */ +#define CPU(obj) ((CPUState *)(obj)) + #define CPU_CLASS(class) OBJECT_CLASS_CHECK(CPUClass, (class), TYPE_CPU) #define CPU_GET_CLASS(obj) OBJECT_GET_CLASS(CPUClass, (obj), TYPE_CPU)