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| author | M. Vefa Bicakci <m.v.b@runbox.com> | 2018-07-24 08:45:47 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-17 21:03:48 +0200 |
| commit | 0ae4fd9024fd15a2d5cf6a50d4bc116e6ea9d5fe (patch) | |
| tree | 0366ce3124e9d1427883b24b706b8915a0d0c01a | |
| parent | 4805211684efad5dff777b1e1846bc6e0aff6da4 (diff) | |
| download | linux-0ae4fd9024fd15a2d5cf6a50d4bc116e6ea9d5fe.tar.gz | |
xen/pv: Call get_cpu_address_sizes to set x86_virt/phys_bits
commit 405c018a25fe464dc68057bbc8014a58f2bd4422 upstream.
Commit d94a155c59c9 ("x86/cpu: Prevent cpuinfo_x86::x86_phys_bits
adjustment corruption") has moved the query and calculation of the
x86_virt_bits and x86_phys_bits fields of the cpuinfo_x86 struct
from the get_cpu_cap function to a new function named
get_cpu_address_sizes.
One of the call sites related to Xen PV VMs was unfortunately missed
in the aforementioned commit. This prevents successful boot-up of
kernel versions 4.17 and up in Xen PV VMs if CONFIG_DEBUG_VIRTUAL
is enabled, due to the following code path:
enlighten_pv.c::xen_start_kernel
mmu_pv.c::xen_reserve_special_pages
page.h::__pa
physaddr.c::__phys_addr
physaddr.h::phys_addr_valid
phys_addr_valid uses boot_cpu_data.x86_phys_bits to validate physical
addresses. boot_cpu_data.x86_phys_bits is no longer populated before
the call to xen_reserve_special_pages due to the aforementioned commit
though, so the validation performed by phys_addr_valid fails, which
causes __phys_addr to trigger a BUG, preventing boot-up.
Signed-off-by: M. Vefa Bicakci <m.v.b@runbox.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: xen-devel@lists.xenproject.org
Cc: x86@kernel.org
Cc: stable@vger.kernel.org # for v4.17 and up
Fixes: d94a155c59c9 ("x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption")
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/cpu.h | 1 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 3 |
3 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9eda6f730ec4e7..b41b72bd8bb85a 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -905,7 +905,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c) apply_forced_caps(c); } -static void get_cpu_address_sizes(struct cpuinfo_x86 *c) +void get_cpu_address_sizes(struct cpuinfo_x86 *c) { u32 eax, ebx, ecx, edx; diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index e59c0ea82a33ac..7b229afa0a37a6 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -46,6 +46,7 @@ extern const struct cpu_dev *const __x86_cpu_dev_start[], *const __x86_cpu_dev_end[]; extern void get_cpu_cap(struct cpuinfo_x86 *c); +extern void get_cpu_address_sizes(struct cpuinfo_x86 *c); extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c); extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c); extern u32 get_scattered_cpuid_leaf(unsigned int level, diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 439a94bf89adb7..c5e3f2acc7f0ac 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1259,6 +1259,9 @@ asmlinkage __visible void __init xen_start_kernel(void) get_cpu_cap(&boot_cpu_data); x86_configure_nx(); + /* Determine virtual and physical address sizes */ + get_cpu_address_sizes(&boot_cpu_data); + /* Let's presume PV guests always boot on vCPU with id 0. */ per_cpu(xen_vcpu_id, 0) = 0; |