Commit 0935e5f7 authored by Ralf Ramsauer's avatar Ralf Ramsauer Committed by Borislav Petkov
Browse files

x86/jailhouse: Improve setup data version comparison 



Soon, setup_data will contain information on passed-through platform
UARTs. This requires some preparational work for the sanity check of the
header and the check of the version.

Use the following strategy:

  1. Ensure that the header declares at least enough space for the
     version and the compatible_version as it must hold that fields for
     any version. The location and semantics of header+version fields
     will never change.

  2. Copy over data -- as much as as possible. The length is either
     limited by the header length or the length of setup_data.

  3. Things are now in place -- sanity check if the header length
     complies the actual version.

For future versions of the setup_data, only step 3 requires alignment.

Signed-off-by: default avatarRalf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: jailhouse-dev@googlegroups.com
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191010102102.421035-2-ralf.ramsauer@oth-regensburg.de
parent 4fb7d087

arch/x86/include/uapi/asm/bootparam.h

+13 −9
Original line number Diff line number Diff line
@@ -139,8 +139,11 @@ struct boot_e820_entry { 
 * setup data structure.

 */

struct jailhouse_setup_data {

	struct {

		__u16	version;

		__u16	compatible_version;

	} __attribute__((packed)) hdr;

	struct {

		__u16	pm_timer_address;

		__u16	num_cpus;

		__u64	pci_mmconfig_base;
@@ -148,6 +151,7 @@ struct jailhouse_setup_data { 
		__u32	apic_khz;

		__u8	standard_ioapic;

		__u8	cpu_ids[255];

	} __attribute__((packed)) v1;

} __attribute__((packed));



/* The so-called "zeropage" */

arch/x86/kernel/jailhouse.c

+32 −19
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ 
#include <asm/jailhouse_para.h>



static __initdata struct jailhouse_setup_data setup_data;

#define SETUP_DATA_V1_LEN	(sizeof(setup_data.hdr) + sizeof(setup_data.v1))



static unsigned int precalibrated_tsc_khz;



static uint32_t jailhouse_cpuid_base(void)
@@ -45,7 +47,7 @@ static void jailhouse_get_wallclock(struct timespec64 *now) 


static void __init jailhouse_timer_init(void)

{

	lapic_timer_period = setup_data.apic_khz * (1000 / HZ);

	lapic_timer_period = setup_data.v1.apic_khz * (1000 / HZ);

}



static unsigned long jailhouse_get_tsc(void)
@@ -88,14 +90,14 @@ static void __init jailhouse_get_smp_config(unsigned int early) 


	register_lapic_address(0xfee00000);



	for (cpu = 0; cpu < setup_data.num_cpus; cpu++) {

		generic_processor_info(setup_data.cpu_ids[cpu],

	for (cpu = 0; cpu < setup_data.v1.num_cpus; cpu++) {

		generic_processor_info(setup_data.v1.cpu_ids[cpu],

				       boot_cpu_apic_version);

	}



	smp_found_config = 1;



	if (setup_data.standard_ioapic) {

	if (setup_data.v1.standard_ioapic) {

		mp_register_ioapic(0, 0xfec00000, gsi_top, &ioapic_cfg);



		/* Register 1:1 mapping for legacy UART IRQs 3 and 4 */
@@ -126,9 +128,9 @@ static int __init jailhouse_pci_arch_init(void) 
		pcibios_last_bus = 0xff;



#ifdef CONFIG_PCI_MMCONFIG

	if (setup_data.pci_mmconfig_base) {

	if (setup_data.v1.pci_mmconfig_base) {

		pci_mmconfig_add(0, 0, pcibios_last_bus,

				 setup_data.pci_mmconfig_base);

				 setup_data.v1.pci_mmconfig_base);

		pci_mmcfg_arch_init();

	}

#endif
@@ -139,6 +141,7 @@ static int __init jailhouse_pci_arch_init(void) 
static void __init jailhouse_init_platform(void)

{

	u64 pa_data = boot_params.hdr.setup_data;

	unsigned long setup_data_len;

	struct setup_data header;

	void *mapping;
@@ -163,16 +166,8 @@ static void __init jailhouse_init_platform(void) 
		memcpy(&header, mapping, sizeof(header));

		early_memunmap(mapping, sizeof(header));



		if (header.type == SETUP_JAILHOUSE &&

		    header.len >= sizeof(setup_data)) {

			pa_data += offsetof(struct setup_data, data);



			mapping = early_memremap(pa_data, sizeof(setup_data));

			memcpy(&setup_data, mapping, sizeof(setup_data));

			early_memunmap(mapping, sizeof(setup_data));



		if (header.type == SETUP_JAILHOUSE)

			break;

		}



		pa_data = header.next;

	}
@@ -180,13 +175,27 @@ static void __init jailhouse_init_platform(void) 
	if (!pa_data)

		panic("Jailhouse: No valid setup data found");



	if (setup_data.compatible_version > JAILHOUSE_SETUP_REQUIRED_VERSION)

		panic("Jailhouse: Unsupported setup data structure");

	/* setup data must at least contain the header */

	if (header.len < sizeof(setup_data.hdr))

		goto unsupported;



	pmtmr_ioport = setup_data.pm_timer_address;

	pa_data += offsetof(struct setup_data, data);

	setup_data_len = min_t(unsigned long, sizeof(setup_data),

			       (unsigned long)header.len);

	mapping = early_memremap(pa_data, setup_data_len);

	memcpy(&setup_data, mapping, setup_data_len);

	early_memunmap(mapping, setup_data_len);



	if (setup_data.hdr.version == 0 ||

	    setup_data.hdr.compatible_version !=

		JAILHOUSE_SETUP_REQUIRED_VERSION ||

	    (setup_data.hdr.version >= 1 && header.len < SETUP_DATA_V1_LEN))

		goto unsupported;



	pmtmr_ioport = setup_data.v1.pm_timer_address;

	pr_debug("Jailhouse: PM-Timer IO Port: %#x\n", pmtmr_ioport);



	precalibrated_tsc_khz = setup_data.tsc_khz;

	precalibrated_tsc_khz = setup_data.v1.tsc_khz;

	setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);



	pci_probe = 0;
@@ -196,6 +205,10 @@ static void __init jailhouse_init_platform(void) 
	 * are none in a non-root cell.

	 */

	disable_acpi();

	return;



unsupported:

	panic("Jailhouse: Unsupported setup data structure");

}



bool jailhouse_paravirt(void)

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