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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-24 09:18:48 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-24 09:18:48 -0800 |
commit | b24e2bdde4af656bb0679a101265ebb8f8735d3c (patch) | |
tree | 4a7bcc9bb7568136615a356dcc237c6f3e7c1cc1 /arch/x86 | |
parent | 84257ce6b798a0eed0b4637694137be941903cf7 (diff) | |
parent | 5054daa285beaf706f051fbd395dc36c9f0f907f (diff) | |
download | linux-b24e2bdde4af656bb0679a101265ebb8f8735d3c.tar.bz2 |
Merge tag 'stable/for-linus-4.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen bugfixes from David Vrabel:
"Xen regression and bug fixes for 4.0-rc1
- Fix two regressions introduced in 4.0-rc1 affecting PV/PVH guests
in certain configurations.
- Prevent pvscsi frontends bypassing backend checks.
- Allow privcmd hypercalls to be preempted even on kernel with
voluntary preemption. This fixes soft-lockups with long running
toolstack hypercalls (e.g., when creating/destroying large
domains)"
* tag 'stable/for-linus-4.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: Initialize cr4 shadow for 64-bit PV(H) guests
xen-scsiback: mark pvscsi frontend request consumed only after last read
x86/xen: allow privcmd hypercalls to be preempted
x86/xen: Make sure X2APIC_ENABLE bit of MSR_IA32_APICBASE is not set
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/kernel/entry_32.S | 3 | ||||
-rw-r--r-- | arch/x86/kernel/entry_64.S | 3 | ||||
-rw-r--r-- | arch/x86/xen/enlighten.c | 20 |
3 files changed, 25 insertions, 1 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 000d4199b03e..31e2d5bf3e38 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -982,6 +982,9 @@ ENTRY(xen_hypervisor_callback) ENTRY(xen_do_upcall) 1: mov %esp, %eax call xen_evtchn_do_upcall +#ifndef CONFIG_PREEMPT + call xen_maybe_preempt_hcall +#endif jmp ret_from_intr CFI_ENDPROC ENDPROC(xen_hypervisor_callback) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index db13655c3a2a..10074ad9ebf8 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1208,6 +1208,9 @@ ENTRY(xen_do_hypervisor_callback) # do_hypervisor_callback(struct *pt_regs) popq %rsp CFI_DEF_CFA_REGISTER rsp decl PER_CPU_VAR(irq_count) +#ifndef CONFIG_PREEMPT + call xen_maybe_preempt_hcall +#endif jmp error_exit CFI_ENDPROC END(xen_do_hypervisor_callback) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index bd8b8459c3d0..5240f563076d 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1070,6 +1070,23 @@ static inline void xen_write_cr8(unsigned long val) BUG_ON(val); } #endif + +static u64 xen_read_msr_safe(unsigned int msr, int *err) +{ + u64 val; + + val = native_read_msr_safe(msr, err); + switch (msr) { + case MSR_IA32_APICBASE: +#ifdef CONFIG_X86_X2APIC + if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31)))) +#endif + val &= ~X2APIC_ENABLE; + break; + } + return val; +} + static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high) { int ret; @@ -1240,7 +1257,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .wbinvd = native_wbinvd, - .read_msr = native_read_msr_safe, + .read_msr = xen_read_msr_safe, .write_msr = xen_write_msr_safe, .read_tsc = native_read_tsc, @@ -1741,6 +1758,7 @@ asmlinkage __visible void __init xen_start_kernel(void) #ifdef CONFIG_X86_32 i386_start_kernel(); #else + cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */ x86_64_start_reservations((char *)__pa_symbol(&boot_params)); #endif } |