RE: [Xen-devel] [PATCH][SVM] fix pae for guests on 32bit HV

["Nakajima, Jun" <jun.nakajima@xxxxxxxxx>]

Woller, Thomas wrote:
> SVM patch to ensure that PAE bit is set for 32bit guests on 32bit PAE,
> by using paging levels>=3 rather than ifdef i386.  This patch fixes
> the "black screen" hang issue when building w/ XEN_TARGET_X86_PAE=y on
> 32bit.
> 
> Tested linux debian and win2003EE guests with pae=1.  The linux guest
> boots without error, while the windows guest sometimes hits a bug() in
> shadow.c.  Both VT and SVM encounter the same bug below.

The current shadow code does not support PAE guests on the PAE Xen. It's
much harder given (compared with x64-64) the limited bits in page_info.
Should work on the 64-bit Xen. Anyway, we need to cleanly kill such
guests on the PAE Xen.

> 
> Applies cleanly to 9638.
> 
> Please apply to xenbits.
> 
> Please apply to 3.0.2 testing.
> 
> Signed-off-by: Tom Woller <thomas.woller@xxxxxxx>
> 
> -------------------------------------------------------------
> Here are the stack traces from the crashes on VT and SVM boxes.
> 
> (XEN) BUG at shadow.c:3183
> (XEN) ----[ Xen-3.0-unstable    Not tainted ]----
> (XEN) CPU:    0
> (XEN) EIP:    e008:[<ff12e891>] gva_to_gpa_pae+0x21/0x30
> (XEN) EFLAGS: 00010292   CONTEXT: hypervisor
> (XEN) eax: 00000000   ebx: 00430e25   ecx: 00002550   edx: 00000000
> (XEN) esi: ff183fb4   edi: ffbd3280   ebp: ff183fb4   esp: ff183f34
> (XEN) cr0: 8005003b   cr3: 00ffe000
> (XEN) ds: e010   es: e010   fs: e010   gs: e010   ss: e010   cs: e008
> (XEN) Xen stack trace from esp=ff183f34:
> (XEN)    ff167dbc ff16ab61 00000c6f ff135815 00430e25 00000005
> ffbbe500 ff1524cf
> (XEN)    00430e25 ff18e110 ffbd3280 ff1504df 00430e25 00000301
> ffbd3280 ff154c1c
> (XEN)    ffbd3280 00000000 4c69cfbc 000000a8 c0496000 00000000
> c0496000 00000000
> (XEN)    ff183fb4 000000a8 00000000 00001000 80087000 80087008
> 0005ffd8 ff1554e2
> (XEN)    00001000 80050033 00645000 80087000 80087008 0005ffd8
> 00000671 00050010
> (XEN)    00414e85 00b90008 00000000 0005fc50 00000202 00000010
> 00000010 00000030
> (XEN)    00000000 00000000 ffbd3280
> (XEN) Xen call trace:
> (XEN)    [<ff12e891>] gva_to_gpa_pae+0x21/0x30
> (XEN)    [<ff135815>] gva_to_gpa+0x25/0x30
> (XEN)    [<ff1524cf>] vmx_do_page_fault+0x9f/0x170
> (XEN)    [<ff1504df>] cpu_has_pending_irq+0x3f/0x60
> (XEN)    [<ff154c1c>] vmx_vmexit_handler+0x85c/0x940
> (XEN)    [<ff1554e2>] vmx_asm_vmexit_handler+0x22/0x30
> (XEN)
> (XEN)
> (XEN) ****************************************
> (XEN) Panic on CPU 0:
> (XEN) CPU0 FATAL TRAP: vector = 6 (invalid opcode)
> (XEN) ****************************************
> (XEN)
> 
> 
> 
> (XEN) BUG at shadow.c:3183
> (XEN) ----[ Xen-3.0-unstable    Not tainted ]----
> (XEN) CPU:    0
> (XEN) EIP:    e008:[<ff12e891>] gva_to_gpa_pae+0x21/0x30
> (XEN) EFLAGS: 00010296   CONTEXT: hypervisor
> (XEN) eax: 00000000   ebx: ff22d000   ecx: 000021e3   edx: 00000000
> (XEN) esi: ff22e080   edi: ff22e080   ebp: 00430e25   esp: ff183ea4
> (XEN) cr0: 80050033   cr3: 00f21000
> (XEN) ds: e010   es: e010   fs: 0000   gs: 0000   ss: e010   cs: e008
> (XEN) Xen stack trace from esp=ff183ea4:
> (XEN)    ff167dbc ff16ab61 00000c6f ff135815 00430e25 00000010
> 0005ffd8 ff14e669
> (XEN)    00430e25 ff183fb4 00000007 ff22e080 ffbe3718 ffbe2080
> ff22e080 ff14f8f8
> (XEN)    ffbe3718 ff18e110 ff190684 00000000 ff183fb4 ff22e080
> 00000030 ff14d608
> (XEN)    ff22e080 0007a120 00000000 ff22d000 42a17620 ff22e080
> 4299d500 ff1181c0
> (XEN)    4299d707 00000030 ff22e080 00000030 42a17620 00000030
> ff22e080 ff115467
> (XEN)    12a1d083 00000006 ff22d000 00000000 00000030 ff18e110
> ffbfee80 ff1118ba
> (XEN)    42a17620 00000030 00000000 ff22e080 ff22e080 00000000
> 4299d6f1 00000030
> (XEN)    ff183f88 00000000 80000011 00000000 ff22e080 00000000
> 00000007 00001000
> (XEN)    80087000 80087008 0005ffd8 ff150271 00001000 80000011
> 00645000 80087000
> (XEN)    80087008 0005ffd8 00000020 00000000 00430e25 00000008
> 00000086 0005ffbc
> (XEN)    00000010 00000010 00000010 00000030 00000000 00000000
> ff22e080 (XEN) Xen call trace:
> (XEN)    [<ff12e891>] gva_to_gpa_pae+0x21/0x30
> (XEN)    [<ff135815>] gva_to_gpa+0x25/0x30
> (XEN)    [<ff14e669>] svm_vmexit_handler+0xd09/0x1a60
> (XEN)    [<ff14f8f8>] svm_do_resume+0x48/0xe0
> (XEN)    [<ff14d608>] arch_svm_do_resume+0x78/0x90
> (XEN)    [<ff1181c0>] continue_running+0x10/0x40
> (XEN)    [<ff115467>] reprogram_timer+0x27/0xe0
> (XEN)    [<ff1118ba>] timer_softirq_action+0x12a/0x150
> (XEN)    [<ff150271>] svm_asm_do_launch+0x71/0x80
> (XEN)
> (XEN)
> (XEN) ****************************************
> (XEN) Panic on CPU 0:
> (XEN) CPU0 FATAL TRAP: vector = 6 (invalid opcode)
> (XEN) ****************************************


Jun
---
Intel Open Source Technology Center

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