Commit 1f435716 authored by Eduardo Habkost's avatar Eduardo Habkost
Browse files

pc: Use "min-[x]level" on compat_props 

Since the automatic cpuid-level code was introduced in commit
c39c0edf ("target-i386: Automatically
set level/xlevel/xlevel2 when needed"), the CPU model tables just define
the default CPUID level code (set using "min-level").  Setting
"[x]level" forces CPUID level to a specific value and disable the
automatic-level logic.

But the PC compat code was not updated and the existing "[x]level"
compat properties broke compatibility for people using features that
triggered the auto-level code.  To keep previous behavior, we should set
"min-[x]level" instead of "[x]level" on compat_props.

This was not a problem for most cases, because old machine-types don't
have full-cpuid-auto-level enabled.  The only common use case it broke
was the CPUID[7] auto-level code, that was already enabled since the
first CPUID[7] feature was introduced (in QEMU 1.4.0).

This causes the regression reported at:
https://bugzilla.redhat.com/show_bug.cgi?id=1454641



Change the PC compat code to use "min-[x]level" instead of "[x]level" on
compat_props, and add new test cases to ensure we don't break this
again.

Reported-by: default avatar"Guo, Zhiyi" <zhguo@redhat.com>
Fixes: c39c0edf ("target-i386: Automatically set level/xlevel/xlevel2 when needed")
Cc: qemu-stable@nongnu.org
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent cb8b8ef4

include/hw/i386/pc.h

+21 −21
Original line number Diff line number Diff line
@@ -566,75 +566,75 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); 
        .value    = "off",\

    },{\

        .driver   = "qemu64" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(4),\

    },{\

        .driver   = "kvm64" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(5),\

    },{\

        .driver   = "pentium3" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(2),\

    },{\

        .driver   = "n270" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(5),\

    },{\

        .driver   = "Conroe" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(4),\

    },{\

        .driver   = "Penryn" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(4),\

    },{\

        .driver   = "Nehalem" "-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(4),\

    },{\

        .driver   = "n270" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Penryn" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Conroe" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Nehalem" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Westmere" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "SandyBridge" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "IvyBridge" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Haswell" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Haswell-noTSX" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Broadwell" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver   = "Broadwell-noTSX" "-" TYPE_X86_CPU,\

        .property = "xlevel",\

        .property = "min-xlevel",\

        .value    = stringify(0x8000000a),\

    },{\

        .driver = TYPE_X86_CPU,\
@@ -860,7 +860,7 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); 
        .value    = stringify(2),\

    },{\

        .driver   = "Conroe-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(2),\

    },{\

        .driver   = "Penryn-" TYPE_X86_CPU,\
@@ -868,7 +868,7 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); 
        .value    = stringify(2),\

    },{\

        .driver   = "Penryn-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(2),\

    },{\

        .driver   = "Nehalem-" TYPE_X86_CPU,\
@@ -876,7 +876,7 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); 
        .value    = stringify(2),\

    },{\

        .driver   = "Nehalem-" TYPE_X86_CPU,\

        .property = "level",\

        .property = "min-level",\

        .value    = stringify(2),\

    },{\

        .driver   = "virtio-net-pci",\

tests/test-x86-cpuid-compat.c

+38 −0
Original line number Diff line number Diff line
@@ -313,6 +313,44 @@ int main(int argc, char **argv) 
    add_cpuid_test("x86/cpuid/auto-xlevel2/pc-2.7",

                   "-machine pc-i440fx-2.7 -cpu 486,+xstore",

                   "xlevel2", 0);

    /*

     * QEMU 1.4.0 had auto-level enabled for CPUID[7], already,

     * and the compat code that sets default level shouldn't

     * disable the auto-level=7 code:

     */

    add_cpuid_test("x86/cpuid/auto-level7/pc-i440fx-1.4/off",

                   "-machine pc-i440fx-1.4 -cpu Nehalem",

                   "level", 2);

    add_cpuid_test("x86/cpuid/auto-level7/pc-i440fx-1.5/on",

                   "-machine pc-i440fx-1.4 -cpu Nehalem,+smap",

                   "level", 7);

    add_cpuid_test("x86/cpuid/auto-level7/pc-i440fx-2.3/off",

                   "-machine pc-i440fx-2.3 -cpu Penryn",

                   "level", 4);

    add_cpuid_test("x86/cpuid/auto-level7/pc-i440fx-2.3/on",

                   "-machine pc-i440fx-2.3 -cpu Penryn,+erms",

                   "level", 7);

    add_cpuid_test("x86/cpuid/auto-level7/pc-i440fx-2.9/off",

                   "-machine pc-i440fx-2.9 -cpu Conroe",

                   "level", 10);

    add_cpuid_test("x86/cpuid/auto-level7/pc-i440fx-2.9/on",

                   "-machine pc-i440fx-2.9 -cpu Conroe,+erms",

                   "level", 10);



    /*

     * xlevel doesn't have any feature that triggers auto-level

     * code on old machine-types.  Just check that the compat code

     * is working correctly:

     */

    add_cpuid_test("x86/cpuid/xlevel-compat/pc-i440fx-2.3",

                   "-machine pc-i440fx-2.3 -cpu SandyBridge",

                   "xlevel", 0x8000000a);

    add_cpuid_test("x86/cpuid/xlevel-compat/pc-i440fx-2.4/npt-off",

                   "-machine pc-i440fx-2.4 -cpu SandyBridge,",

                   "xlevel", 0x80000008);

    add_cpuid_test("x86/cpuid/xlevel-compat/pc-i440fx-2.4/npt-on",

                   "-machine pc-i440fx-2.4 -cpu SandyBridge,+npt",

                   "xlevel", 0x80000008);



    /* Test feature parsing */

    add_feature_test("x86/cpuid/features/plus",