When booting a kernel which has been built with CONFIG_AMD_MEM_ENCRYPT
enabled as a Xen pv guest a warning is issued for each processor:
[ 5.964347] ------------[ cut here ]------------
[ 5.968314] WARNING: CPU: 0 PID: 1 at /home/gross/linux/head/arch/x86/xen/enlighten_pv.c:660 get_trap_addr+0x59/0x90
[ 5.972321] Modules linked in:
[ 5.976313] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 5.11.0-rc5-default #75
[ 5.980313] Hardware name: Dell Inc. OptiPlex 9020/0PC5F7, BIOS A05 12/05/2013
[ 5.984313] RIP: e030:get_trap_addr+0x59/0x90
[ 5.988313] Code: 42 10 83 f0 01 85 f6 74 04 84 c0 75 1d b8 01 00 00 00 c3 48 3d 00 80 83 82 72 08 48 3d 20 81 83 82 72 0c b8 01 00 00 00 eb db <0f> 0b 31 c0 c3 48 2d 00 80 83 82 48 ba 72 1c c7 71 1c c7 71 1c 48
[ 5.992313] RSP: e02b:ffffc90040033d38 EFLAGS: 00010202
[ 5.996313] RAX: 0000000000000001 RBX: ffffffff82a141d0 RCX: ffffffff8222ec38
[ 6.000312] RDX: ffffffff8222ec38 RSI: 0000000000000005 RDI: ffffc90040033d40
[ 6.004313] RBP: ffff8881003984a0 R08: 0000000000000007 R09: ffff888100398000
[ 6.008312] R10: 0000000000000007 R11: ffffc90040246000 R12: ffff8884082182a8
[ 6.012313] R13: 0000000000000100 R14: 000000000000001d R15: ffff8881003982d0
[ 6.016316] FS: 0000000000000000(0000) GS:ffff888408200000(0000) knlGS:0000000000000000
[ 6.020313] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6.024313] CR2: ffffc900020ef000 CR3: 000000000220a000 CR4: 0000000000050660
[ 6.028314] Call Trace:
[ 6.032313] cvt_gate_to_trap.part.7+0x3f/0x90
[ 6.036313] ? asm_exc_double_fault+0x30/0x30
[ 6.040313] xen_convert_trap_info+0x87/0xd0
[ 6.044313] xen_pv_cpu_up+0x17a/0x450
[ 6.048313] bringup_cpu+0x2b/0xc0
[ 6.052313] ? cpus_read_trylock+0x50/0x50
[ 6.056313] cpuhp_invoke_callback+0x80/0x4c0
[ 6.060313] _cpu_up+0xa7/0x140
[ 6.064313] cpu_up+0x98/0xd0
[ 6.068313] bringup_nonboot_cpus+0x4f/0x60
[ 6.072313] smp_init+0x26/0x79
[ 6.076313] kernel_init_freeable+0x103/0x258
[ 6.080313] ? rest_init+0xd0/0xd0
[ 6.084313] kernel_init+0xa/0x110
[ 6.088313] ret_from_fork+0x1f/0x30
[ 6.092313] ---[ end trace be9ecf17dceeb4f3 ]---
Reason is that there is no Xen pv trap entry for X86_TRAP_VC.
Fix that by defining a trap entry for X86_TRAP_VC in Xen pv mode.
Fixes: 0786138c78e793 ("x86/sev-es: Add a Runtime #VC Exception Handler")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.10
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
arch/x86/include/asm/idtentry.h | 3 +++
arch/x86/xen/enlighten_pv.c | 11 +++++++++++
arch/x86/xen/xen-asm.S | 3 +++
3 files changed, 17 insertions(+)
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 247a60a47331..115a76e77e65 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -609,6 +609,9 @@ DECLARE_IDTENTRY_DF(X86_TRAP_DF, exc_double_fault);
/* #VC */
#ifdef CONFIG_AMD_MEM_ENCRYPT
DECLARE_IDTENTRY_VC(X86_TRAP_VC, exc_vmm_communication);
+#ifdef CONFIG_XEN_PV
+DECLARE_IDTENTRY_RAW(X86_TRAP_VC, xenpv_exc_vmm_communication);
+#endif
#endif
#ifdef CONFIG_XEN_PV
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 4409306364dc..82948251f57b 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -583,6 +583,14 @@ DEFINE_IDTENTRY_RAW(xenpv_exc_debug)
exc_debug(regs);
}
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+DEFINE_IDTENTRY_RAW(xenpv_exc_vmm_communication)
+{
+ /* This should never happen and there is no way to handle it. */
+ panic("X86_TRAP_VC in Xen PV mode.");
+}
+#endif
+
struct trap_array_entry {
void (*orig)(void);
void (*xen)(void);
@@ -625,6 +633,9 @@ static struct trap_array_entry trap_array[] = {
TRAP_ENTRY(exc_coprocessor_error, false ),
TRAP_ENTRY(exc_alignment_check, false ),
TRAP_ENTRY(exc_simd_coprocessor_error, false ),
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ TRAP_ENTRY_REDIR(exc_vmm_communication, true ),
+#endif
};
static bool __ref get_trap_addr(void **addr, unsigned int ist)
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 1cb0e84b9161..16f4db35de44 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -175,6 +175,9 @@ xen_pv_trap asm_exc_alignment_check
xen_pv_trap asm_exc_machine_check
#endif /* CONFIG_X86_MCE */
xen_pv_trap asm_exc_simd_coprocessor_error
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+xen_pv_trap asm_xenpv_exc_vmm_communication
+#endif /* CONFIG_AMD_MEM_ENCRYPT */
#ifdef CONFIG_IA32_EMULATION
xen_pv_trap entry_INT80_compat
#endif
--
2.26.2
