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From: "Johannes Luber" <JALuber@gmx.de>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] target_phys_addr_t definition
Date: Fri, 11 Sep 2009 11:39:13 +0200	[thread overview]
Message-ID: <20090911093913.324670@gmx.net> (raw)

Hi,

I've been looking through the sources and stumbled over targphys.h, which contains:

/* target_phys_addr_t is the type of a physical address (its size can
   be different from 'target_ulong'). We have sizeof(target_phys_addr)
   = max(sizeof(unsigned long),
   sizeof(size_of_target_physical_address)) because we must pass a
   host pointer to memory operations in some cases */

#if TARGET_PHYS_ADDR_BITS == 32
typedef uint32_t target_phys_addr_t;
#define TARGET_PHYS_ADDR_MAX UINT32_MAX
#define TARGET_FMT_plx "%08x"
#elif TARGET_PHYS_ADDR_BITS == 64
typedef uint64_t target_phys_addr_t;
#define TARGET_PHYS_ADDR_MAX UINT64_MAX
#define TARGET_FMT_plx "%016" PRIx64
#endif

The comment says "sizeof(target_phys_addr) = max(...)" yet I don't the actual definition depending on the host at all. This means that on 64 bit hosts things are going wrong. sizeof(uint32_t) will be always 4 and actually using sizeof(unsigned long) will still result on 64-bit Windows in 4, despite pointer having 8 bytes.

As the comment remarks this won't work with physical pointers which reference pages beyond the 4 GB limit (unless the pointers don't have always some high bits set). So my question is: Does Qemu support 64-bit compilation for hosts correctly?

Best regards,
Johannes
-- 
Neu: GMX Doppel-FLAT mit Internet-Flatrate + Telefon-Flatrate
für nur 19,99 Euro/mtl.!* http://portal.gmx.net/de/go/dsl02

             reply	other threads:[~2009-09-11  9:39 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-11  9:39 Johannes Luber [this message]
     [not found] ` <m3zl91zsqd.fsf@neno.mitica>
2009-09-11 11:05   ` [Qemu-devel] Re: target_phys_addr_t definition Johannes Luber

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