Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Various fixes
* libdaxctl support to correctly align devdax character devices (Jingqi)
* initial-all-set support for l

Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Various fixes
* libdaxctl support to correctly align devdax character devices (Jingqi)
* initial-all-set support for live migration (Jay)
* forbid '-numa node, mem' for 5.1 and newer machine types (Igor)
* x87 fixes (Joseph)
* Tighten memory_region_access_valid (Michael) and fix fallout (myself)
* Replay fixes (Pavel)

# gpg: Signature made Fri 26 Jun 2020 14:42:17 BST
# gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg: issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (31 commits)
i386: Mask SVM features if nested SVM is disabled
ibex_uart: fix XOR-as-pow
vmport: move compat properties to hw_compat_5_0
hyperv: vmbus: Remove the 2nd IRQ
kvm: i386: allow TSC to differ by NTP correction bounds without TSC scaling
numa: forbid '-numa node, mem' for 5.1 and newer machine types
osdep: Make MIN/MAX evaluate arguments only once
target/i386: Add notes for versioned CPU models
target/i386: reimplement fpatan using floatx80 operations
target/i386: reimplement fyl2x using floatx80 operations
target/i386: reimplement fyl2xp1 using floatx80 operations
target/i386: reimplement fprem, fprem1 using floatx80 operations
softfloat: return low bits of quotient from floatx80_modrem
softfloat: do not set denominator high bit for floatx80 remainder
softfloat: do not return pseudo-denormal from floatx80 remainder
softfloat: fix floatx80 remainder pseudo-denormal check for zero
softfloat: merge floatx80_mod and floatx80_rem
target/i386: reimplement f2xm1 using floatx80 operations
xen: Actually fix build without passthrough
Makefile: Install qemu-[qmp/ga]-ref.* into the directory "interop"
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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target/i386: reimplement f2xm1 using floatx80 operations

The x87 f2xm1 emulation is currently based around conversion to
double. This is inherently unsuitable for a good emulation of any
floatx80 o

target/i386: reimplement f2xm1 using floatx80 operations

The x87 f2xm1 emulation is currently based around conversion to
double. This is inherently unsuitable for a good emulation of any
floatx80 operation, even before considering that it is a particularly
naive implementation using double (computing with pow and then
subtracting 1 rather than attempting a better emulation using expm1).

Reimplement using the soft-float operations, including additions and
multiplications with higher precision where appropriate to limit
accumulation of errors. I considered reusing some of the m68k code
for transcendental operations, but the instructions don't generally
correspond exactly to x87 operations (for example, m68k has 2^x and
e^x - 1, but not 2^x - 1); to avoid possible accumulation of errors
from applying multiple such operations each rounding to floatx80
precision, I wrote a direct implementation of 2^x - 1 instead. It
would be possible in principle to make the implementation more
efficient by doing the intermediate operations directly with
significands, signs and exponents and not packing / unpacking floatx80
format for each operation, but that would make it significantly more
complicated and it's not clear that's worthwhile; the m68k emulation
doesn't try to do that.

A test is included with many randomly generated inputs. The
assumption of the test is that the result in round-to-nearest mode
should always be one of the two closest floating-point numbers to the
mathematical value of 2^x - 1; the implementation aims to do somewhat
better than that (about 70 correct bits before rounding). I haven't
investigated how accurate hardware is.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>

Message-Id: <alpine.DEB.2.21.2006112341010.18393@digraph.polyomino.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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