linux-kernel - [PATCH 06/10] x86: jailhouse: Avoid access of unsupported platform resources

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Date:   Thu, 16 Nov 2017 08:26:48 +0100
From:   Jan Kiszka <jan.kiszka@...mens.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H . Peter Anvin" <hpa@...or.com>
Cc:     x86@...nel.org,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        jailhouse-dev@...glegroups.com
Subject: [PATCH 06/10] x86: jailhouse: Avoid access of unsupported platform resources

From: Jan Kiszka <jan.kiszka@...mens.com>

We don't have CMOS access, thus we can't set the warm-reset vectors in
do_boot_cpu. There is no RTC, thus also no wall clock. Furthermore,
there are no ISA IRQs and no PIC. So fill the platform callbacks
accordingly.

Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
---
 arch/x86/kernel/jailhouse.c | 10 ++++++++++
 arch/x86/kernel/smpboot.c   |  7 +++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index 8e5b2f0c8a34..cfe8ae0c33a2 100644
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -15,6 +15,7 @@
 #include <asm/apic.h>
 #include <asm/cpu.h>
 #include <asm/hypervisor.h>
+#include <asm/i8259.h>
 #include <asm/setup.h>
 
 #define SETUP_JAILHOUSE		0x53484c4a /* "JLHS" */
@@ -50,6 +51,11 @@ static uint32_t __init jailhouse_detect(void)
 	return jailhouse_cpuid_base();
 }
 
+static void jailhouse_get_wallclock(struct timespec *now)
+{
+	memset(now, 0, sizeof(*now));
+}
+
 #define MAX_RETRIES	5
 #define SMI_TRESHOLD	50000
 
@@ -139,7 +145,11 @@ static void __init jailhouse_init_platform(void)
 	unsigned int cpu;
 
 	x86_init.timers.timer_init	= jailhouse_timer_init;
+	x86_init.irqs.pre_vector_init	= x86_init_noop;
+	legacy_pic			= &null_legacy_pic;
 
+	x86_platform.legacy.rtc = 0;
+	x86_platform.get_wallclock = jailhouse_get_wallclock;
 	x86_platform.calibrate_cpu = jailhouse_calibrate_cpu;
 	x86_platform.calibrate_tsc = jailhouse_calibrate_tsc;
 
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5f59e6bee123..81339dbafeba 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -78,6 +78,7 @@
 #include <asm/realmode.h>
 #include <asm/misc.h>
 #include <asm/qspinlock.h>
+#include <asm/jailhouse_para.h>
 
 /* Number of siblings per CPU package */
 int smp_num_siblings = 1;
@@ -1006,7 +1007,8 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
 	 * the targeted processor.
 	 */
 
-	if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
+	if (get_uv_system_type() != UV_NON_UNIQUE_APIC &&
+	    !jailhouse_paravirt()) {
 
 		pr_debug("Setting warm reset code and vector.\n");
 
@@ -1078,7 +1080,8 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
 	/* mark "stuck" area as not stuck */
 	*trampoline_status = 0;
 
-	if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
+	if (get_uv_system_type() != UV_NON_UNIQUE_APIC &&
+	    !jailhouse_paravirt()) {
 		/*
 		 * Cleanup possible dangling ends...
 		 */
-- 
2.12.3