linux-toradex.git/drivers/hv/hv.c, branch v4.9.120

x86/retpoline/hyperv: Convert assembler indirect jumps

2018-01-17T08:38:59+00:00

commit e70e5892b28c18f517f29ab6e83bd57705104b31 upstream.

Convert all indirect jumps in hyperv inline asm code to use non-speculative
sequences when CONFIG_RETPOLINE is enabled.

Signed-off-by: David Woodhouse 
Signed-off-by: Thomas Gleixner 
Acked-by: Arjan van de Ven 
Acked-by: Ingo Molnar 
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel 
Cc: Andi Kleen 
Cc: Josh Poimboeuf 
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Jiri Kosina 
Cc: Andy Lutomirski 
Cc: Dave Hansen 
Cc: Kees Cook 
Cc: Tim Chen 
Cc: Greg Kroah-Hartman 
Cc: Paul Turner 
Link: https://lkml.kernel.org/r/1515707194-20531-9-git-send-email-dwmw@amazon.co.uk
[ backport to 4.9, hopefully correct, not tested... - gregkh ]
Signed-off-by: Greg Kroah-Hartman

drivers: hv: Turn off write permission on the hypercall page

2017-03-15T02:02:52+00:00

commit 372b1e91343e657a7cc5e2e2bcecd5140ac28119 upstream.

The hypercall page only needs to be executable but currently it is setup to
be writable as well. Fix the issue.

Signed-off-by: K. Y. Srinivasan 
Acked-by: Kees Cook 
Reported-by: Stephen Hemminger 
Tested-by: Stephen Hemminger 
Signed-off-by: Greg Kroah-Hartman

hv: don't reset hv_context.tsc_page on crash

2017-03-12T05:41:49+00:00

commit 56ef6718a1d8d77745033c5291e025ce18504159 upstream.

It may happen that secondary CPUs are still alive and resetting
hv_context.tsc_page will cause a consequent crash in read_hv_clock_tsc()
as we don't check for it being not NULL there. It is safe as we're not
freeing this page anyways.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

hv: init percpu_list in hv_synic_alloc()

2017-03-12T05:41:49+00:00

commit 3c7630d35009e6635e5b58d62de554fd5b6db5df upstream.

Initializing hv_context.percpu_list in hv_synic_alloc() helps to prevent a
crash in percpu_channel_enq() when not all CPUs were online during
initialization and it naturally belongs there.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

hv: allocate synic pages for all present CPUs

2017-03-12T05:41:49+00:00

commit 421b8f20d3c381b215f988b42428f56fc3b82405 upstream.

It may happen that not all CPUs are online when we do hv_synic_alloc() and
in case more CPUs come online later we may try accessing these allocated
structures.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: avoid vfree() on crash

2016-08-31T11:05:40+00:00

When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit

    kernel BUG at mm/vmalloc.c:1530!

as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Support handling messages on multiple CPUs

2016-03-02T00:57:20+00:00

Starting with Windows 2012 R2, message inteerupts can be delivered
on any VCPU in the guest. Support this functionality.

Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: don't manipulate with clocksources on crash

2016-02-08T05:34:12+00:00

clocksource_change_rating() involves mutex usage and can't be called
in interrupt context. It also makes sense to avoid doing redundant work
on crash.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Cleanup vmbus_set_event()

2016-02-08T05:32:57+00:00

Cleanup vmbus_set_event() by inlining the hypercall to post
the event and since the return value of vmbus_set_event() is not checked,
make it void. As part of this cleanup, get rid of the function
hv_signal_event() as it is only callled from vmbus_set_event().

Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

drivers/hv: correct tsc page sequence invalid value

2015-12-15T03:15:05+00:00

Hypervisor Top Level Functional Specification v3/4 says
that TSC page sequence value = -1(0xFFFFFFFF) is used to
indicate that TSC page no longer reliable source of reference
timer. Unfortunately, we found that Windows Hyper-V guest
side implementation uses sequence value = 0 to indicate
that Tsc page no longer valid. This is clearly visible
inside Windows 2012R2 ntoskrnl.exe HvlGetReferenceTime()
function dissassembly:

HvlGetReferenceTime proc near
                 xchg    ax, ax
loc_1401C3132:
                 mov     rax, cs:HvlpReferenceTscPage
                 mov     r9d, [rax]
                 test    r9d, r9d
                 jz      short loc_1401C3176
                 rdtsc
                 mov     rcx, cs:HvlpReferenceTscPage
                 shl     rdx, 20h
                 or      rdx, rax
                 mov     rax, [rcx+8]
                 mov     rcx, cs:HvlpReferenceTscPage
                 mov     r8, [rcx+10h]
                 mul     rdx
                 mov     rax, cs:HvlpReferenceTscPage
                 add     rdx, r8
                 mov     ecx, [rax]
                 cmp     ecx, r9d
                 jnz     short loc_1401C3132
                 jmp     short loc_1401C3184
loc_1401C3176:
                 mov     ecx, 40000020h
                 rdmsr
                 shl     rdx, 20h
                 or      rdx, rax
loc_1401C3184:
                 mov     rax, rdx
                 retn
HvlGetReferenceTime endp

This patch aligns Tsc page invalid sequence value with
Windows Hyper-V guest implementation which is more
compatible with both Hyper-V hypervisor and KVM hypervisor.

Signed-off-by: Andrey Smetanin 
Signed-off-by: Denis V. Lunev 
CC: "K. Y. Srinivasan" 
CC: Haiyang Zhang 
CC: Vitaly Kuznetsov 

Signed-off-by: Denis V. Lunev 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman