graphic: 0.856
vnc: 0.835
device: 0.828
instruction: 0.757
boot: 0.755
socket: 0.627
mistranslation: 0.582
other: 0.553
semantic: 0.450
KVM: 0.348
network: 0.285
assembly: 0.206

Absolutely slow Windows XP SP3 installation

Host: Linux 4.3.3 vanilla x86-64/Qemu 2.5 i686 (mixed env)
Guest: Windows XP Professional SP3 (i686)

This is my launch string:

$ qemu-system-i386 \
-name "Windows XP Professional SP3" \
-vga std \
-net nic,model=pcnet \
-cpu core2duo \
-smp cores=2 \
-cdrom /tmp/en_winxp_pro_with_sp3_vl.iso \
-hda Windows_XP.qcow \
-boot d \
-net nic \
-net user \
-m 1536 \
-localtime

Console output:

warning: TCG doesn't support requested feature: CPUID.01H:EDX.vme [bit 1]
warning: TCG doesn't support requested feature: CPUID.80000001H:EDX.syscall [bit 11]
warning: TCG doesn't support requested feature: CPUID.80000001H:EDX.lm|i64 [bit 29]
warning: TCG doesn't support requested feature: CPUID.01H:EDX.vme [bit 1]
warning: TCG doesn't support requested feature: CPUID.80000001H:EDX.syscall [bit 11]
warning: TCG doesn't support requested feature: CPUID.80000001H:EDX.lm|i64 [bit 29]

After hitting 35% installation more or less stalls (it actually doesn't but it progresses 1% a minute which is totally unacceptable).

That was without KVM acceleration, so perhaps it's how it's meant to be.

With KVM everything is fast and smooth.

For integer workloads such as installing an OS you should expect TCG to be about 12x slower than KVM on average. That is on current master; note that TCG has gotten faster in the last couple of years. See a performance comparison from v2.7.0 to v2.11.0 for SPEC06 here: https://imgur.com/a/5P5zj

I've therefore marked the report as invalid, as I don't think the aforementioned speedups will change your experience dramatically.