On 09.03.20 12:21, Janosch Frank wrote:
> The unpack facility provides the means to setup a protected guest. A
> protected guest can not be introspected by the hypervisor or any
> user/administrator of the machine it is running on.
>
> Protected guests are encrypted at rest and need a special boot
> mechanism via diag308 subcode 8 and 10.
>
> Code 8 sets the PV specific IPLB which is retained seperately from
> those set via code 5.
>
> Code 10 is used to unpack the VM into protected memory, verify its
> integrity and start it.
>
> Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
> Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com> [Changes
> to machine]
As you signed this patch off, Maybe this should rather be a Co-developed-by:
[...]
> {
> S390IPLState *ipl = get_ipl_device();
> @@ -561,7 +581,8 @@ void s390_ipl_reset_request(CPUState *cs, enum s390_reset
> reset_type)
> {
> S390IPLState *ipl = get_ipl_device();
>
> - if (reset_type == S390_RESET_EXTERNAL || reset_type == S390_RESET_REIPL)
> {
> + if (reset_type == S390_RESET_EXTERNAL || reset_type == S390_RESET_REIPL
> ||
> + reset_type == S390_RESET_PV) {
> /* use CPU 0 for full resets */
> ipl->reset_cpu_index = 0;
This looks wrong. In case of an error, you modify the registers of a
theoretically unrelated CPU.
> } else {
> @@ -635,6 +656,38 @@ static void s390_ipl_prepare_qipl(S390CPU *cpu)
> cpu_physical_memory_unmap(addr, len, 1, len);
> }
>
> +int s390_ipl_prepare_pv_header(void)
> +{
> + S390IPLState *ipl = get_ipl_device();
> + IPLBlockPV *ipib_pv = &ipl->iplb_pv.pv;
> + void *hdr = g_malloc(ipib_pv->pv_header_len);
Should there be an upper limit? The guest can allocate quite some memory
this way and theoretically crash the VM.
> + int rc;
> +
> + cpu_physical_memory_read(ipib_pv->pv_header_addr, hdr,
> + ipib_pv->pv_header_len);
Shouldn't we validate if this memory is accessible at all?
> + rc = s390_pv_set_sec_parms((uint64_t)hdr,
> + ipib_pv->pv_header_len);
> + g_free(hdr);
> + return rc;
> +}
> +
> +int s390_ipl_pv_unpack(void)
> +{
> + int i, rc = 0;
NIT: These declarations last.
> + S390IPLState *ipl = get_ipl_device();
> + IPLBlockPV *ipib_pv = &ipl->iplb_pv.pv;
use s390_ipl_get_iplb_pv() and assert that we don't get NULL?
> +
> + for (i = 0; i < ipib_pv->num_comp; i++) {
> + rc = s390_pv_unpack(ipib_pv->components[i].addr,
> + TARGET_PAGE_ALIGN(ipib_pv->components[i].size),
> + ipib_pv->components[i].tweak_pref);
> + if (rc) {
> + break;
> + }
> + }
> + return rc;
> +}
> +
> void s390_ipl_prepare_cpu(S390CPU *cpu)
> {
> S390IPLState *ipl = get_ipl_device();
> diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
> index d4813105db..b2ccdd9dae 100644
> --- a/hw/s390x/ipl.h
> +++ b/hw/s390x/ipl.h
> @@ -15,6 +15,24 @@
> #include "cpu.h"
> #include "hw/qdev-core.h"
>
> +struct IPLBlockPVComp {
> + uint64_t tweak_pref;
> + uint64_t addr;
> + uint64_t size;
> +} QEMU_PACKED;
> +typedef struct IPLBlockPVComp IPLBlockPVComp;
> +
> +struct IPLBlockPV {
> + uint8_t reserved18[87]; /* 0x18 */
> + uint8_t version; /* 0x6f */
> + uint32_t reserved70; /* 0x70 */
> + uint32_t num_comp; /* 0x70 */
> + uint64_t pv_header_addr; /* 0x74 */
> + uint64_t pv_header_len; /* 0x7c */
> + struct IPLBlockPVComp components[];
> +} QEMU_PACKED;
> +typedef struct IPLBlockPV IPLBlockPV;
> +
> struct IplBlockCcw {
> uint8_t reserved0[85];
> uint8_t ssid;
> @@ -71,6 +89,7 @@ union IplParameterBlock {
> union {
> IplBlockCcw ccw;
> IplBlockFcp fcp;
> + IPLBlockPV pv;
> IplBlockQemuScsi scsi;
> };
> } QEMU_PACKED;
> @@ -85,8 +104,11 @@ typedef union IplParameterBlock IplParameterBlock;
>
> int s390_ipl_set_loadparm(uint8_t *loadparm);
> void s390_ipl_update_diag308(IplParameterBlock *iplb);
> +int s390_ipl_prepare_pv_header(void);
> +int s390_ipl_pv_unpack(void);
> void s390_ipl_prepare_cpu(S390CPU *cpu);
> IplParameterBlock *s390_ipl_get_iplb(void);
> +IplParameterBlock *s390_ipl_get_iplb_pv(void);
>
> enum s390_reset {
> /* default is a reset not triggered by a CPU e.g. issued by QMP */
> @@ -94,6 +116,7 @@ enum s390_reset {
> S390_RESET_REIPL,
> S390_RESET_MODIFIED_CLEAR,
> S390_RESET_LOAD_NORMAL,
> + S390_RESET_PV,
> };
> void s390_ipl_reset_request(CPUState *cs, enum s390_reset reset_type);
> void s390_ipl_get_reset_request(CPUState **cs, enum s390_reset *reset_type);
> @@ -133,6 +156,7 @@ struct S390IPLState {
> /*< private >*/
> DeviceState parent_obj;
> IplParameterBlock iplb;
> + IplParameterBlock iplb_pv;
> QemuIplParameters qipl;
> uint64_t start_addr;
> uint64_t compat_start_addr;
> @@ -140,6 +164,7 @@ struct S390IPLState {
> uint64_t compat_bios_start_addr;
> bool enforce_bios;
> bool iplb_valid;
> + bool iplb_valid_pv;
> bool netboot;
> /* reset related properties don't have to be migrated or reset */
> enum s390_reset reset_type;
> @@ -161,9 +186,11 @@ QEMU_BUILD_BUG_MSG(offsetof(S390IPLState, iplb) & 3,
> "alignment of iplb wrong");
>
> #define S390_IPL_TYPE_FCP 0x00
> #define S390_IPL_TYPE_CCW 0x02
> +#define S390_IPL_TYPE_PV 0x05
> #define S390_IPL_TYPE_QEMU_SCSI 0xff
>
> #define S390_IPLB_HEADER_LEN 8
> +#define S390_IPLB_MIN_PV_LEN 148
> #define S390_IPLB_MIN_CCW_LEN 200
> #define S390_IPLB_MIN_FCP_LEN 384
> #define S390_IPLB_MIN_QEMU_SCSI_LEN 200
> @@ -173,16 +200,49 @@ static inline bool iplb_valid_len(IplParameterBlock
> *iplb)
> return be32_to_cpu(iplb->len) <= sizeof(IplParameterBlock);
> }
>
> -static inline bool iplb_valid_ccw(IplParameterBlock *iplb)
> +static inline bool s390_ipl_pv_check_components(IplParameterBlock *iplb)
Still don't like the function name :)
ipl_valid_pv_components() ?
> {
> - return be32_to_cpu(iplb->len) >= S390_IPLB_MIN_CCW_LEN &&
> - iplb->pbt == S390_IPL_TYPE_CCW;
> + IPLBlockPV *ipib_pv = &iplb->pv;
> + int i;
> +
> + if (ipib_pv->num_comp == 0) {
> + return false;
> + }
> +
> + for (i = 0; i < ipib_pv->num_comp; i++) {
> + /* Addr must be 4k aligned */
> + if (ipib_pv->components[i].addr & ~TARGET_PAGE_MASK) {
> + return false;
> + }
> +
> + /* Tweak prefix is monotonically increasing with each component */
> + if (i < ipib_pv->num_comp - 1 &&
> + ipib_pv->components[i].tweak_pref >=
> + ipib_pv->components[i + 1].tweak_pref) {
> + return false;
> + }
> + }
> + return true;
> }
>
> -static inline bool iplb_valid_fcp(IplParameterBlock *iplb)
> +static inline bool iplb_valid(IplParameterBlock *iplb)
> {
> - return be32_to_cpu(iplb->len) >= S390_IPLB_MIN_FCP_LEN &&
> - iplb->pbt == S390_IPL_TYPE_FCP;
> + switch (iplb->pbt) {
> + case S390_IPL_TYPE_FCP:
> + return (be32_to_cpu(iplb->len) >= S390_IPLB_MIN_FCP_LEN &&
> + iplb->pbt == S390_IPL_TYPE_FCP);
> + case S390_IPL_TYPE_CCW:
> + return (be32_to_cpu(iplb->len) >= S390_IPLB_MIN_CCW_LEN &&
> + iplb->pbt == S390_IPL_TYPE_CCW);
That's a refactoring you could have split out.
> + case S390_IPL_TYPE_PV:
> + if(be32_to_cpu(iplb->len) < S390_IPLB_MIN_PV_LEN ||
> + iplb->pbt != S390_IPL_TYPE_PV) {
> + return false;
> + }
> + return s390_ipl_pv_check_components(iplb);
> + default:
> + return false;
> + }
> }
>
> #endif
> diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c
> new file mode 100644
> index 0000000000..ba6409246e
> --- /dev/null
> +++ b/hw/s390x/pv.c
> @@ -0,0 +1,104 @@
> +/*
> + * Secure execution functions
> + *
> + * Copyright IBM Corp. 2020
> + * Author(s):
> + * Janosch Frank <fran...@linux.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +#include "qemu/osdep.h"
> +
> +#include <linux/kvm.h>
> +
> +#include "qemu/error-report.h"
> +#include "sysemu/kvm.h"
> +#include "pv.h"
> +
> +const char *cmd_names[] = {
> + "VM_ENABLE",
> + "VM_DISABLE",
> + "VM_SET_SEC_PARAMS",
> + "VM_UNPACK",
> + "VM_VERIFY",
> + "VM_PREP_RESET",
> + "VM_UNSHARE_ALL",
> +};
> +
> +static int s390_pv_cmd(uint32_t cmd, void *data)
> +{
> + int rc;
> + struct kvm_pv_cmd pv_cmd = {
> + .cmd = cmd,
> + .data = (uint64_t)data,
> + };
> +
> + rc = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
> + if (rc) {
> + error_report("KVM PV command %d (%s) failed: header rc %x rrc %x "
> + "IOCTL rc: %d", cmd, cmd_names[cmd], pv_cmd.rc,
> pv_cmd.rrc,
> + rc);
> + }
> + return rc;
> +}
> +
> +static void s390_pv_cmd_exit(uint32_t cmd, void *data)
> +{
> + int rc;
> +
> + rc = s390_pv_cmd(cmd, data);
> + if (rc) {
> + exit(1);
> + }
> +}
> +
> +int s390_pv_vm_enable(void)
> +{
> + return s390_pv_cmd(KVM_PV_ENABLE, NULL);
> +}
> +
> +void s390_pv_vm_disable(void)
> +{
> + s390_pv_cmd_exit(KVM_PV_DISABLE, NULL);
> +}
> +
> +int s390_pv_set_sec_parms(uint64_t origin, uint64_t length)
> +{
> + struct kvm_s390_pv_sec_parm args = {
> + .origin = origin,
> + .length = length,
> + };
> +
> + return s390_pv_cmd(KVM_PV_VM_SET_SEC_PARMS, &args);
> +}
> +
> +/*
> + * Called for each component in the SE type IPL parameter block 0.
> + */
> +int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak)
> +{
> + struct kvm_s390_pv_unp args = {
> + .addr = addr,
> + .size = size,
> + .tweak = tweak,
> + };
> +
> + return s390_pv_cmd(KVM_PV_VM_UNPACK, &args);
> +}
> +
> +void s390_pv_perf_clear_reset(void)
> +{
> + s390_pv_cmd_exit(KVM_PV_VM_PREP_RESET, NULL);
> +}
> +
> +int s390_pv_verify(void)
> +{
> + return s390_pv_cmd(KVM_PV_VM_VERIFY, NULL);
> +}
> +
> +void s390_pv_unshare(void)
> +{
> + s390_pv_cmd_exit(KVM_PV_VM_UNSHARE_ALL, NULL);
> +}
> diff --git a/hw/s390x/pv.h b/hw/s390x/pv.h
> new file mode 100644
> index 0000000000..e58fbca96a
> --- /dev/null
> +++ b/hw/s390x/pv.h
> @@ -0,0 +1,34 @@
> +/*
> + * Protected Virtualization header
> + *
> + * Copyright IBM Corp. 2020
> + * Author(s):
> + * Janosch Frank <fran...@linux.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or (at
> + * your option) any later version. See the COPYING file in the top-level
> + * directory.
> + */
> +
> +#ifndef HW_S390_PV_H
> +#define HW_S390_PV_H
> +
> +#ifdef CONFIG_KVM
> +int s390_pv_vm_enable(void);
> +void s390_pv_vm_disable(void);
> +int s390_pv_set_sec_parms(uint64_t origin, uint64_t length);
> +int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak);
> +void s390_pv_perf_clear_reset(void);
> +int s390_pv_verify(void);
> +void s390_pv_unshare(void);
> +#else
> +static inline int s390_pv_vm_enable(void) { return 0; }
> +static inline void s390_pv_vm_disable(void) {}
> +static inline int s390_pv_set_sec_parms(uint64_t origin, uint64_t length) {
> return 0; }
> +static inline int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t
> tweak) { return 0; }
> +static inline void s390_pv_perf_clear_reset(void) {}
> +static inline int s390_pv_verify(void) { return 0; }
> +static inline void s390_pv_unshare(void) {}
> +#endif
> +
> +#endif /* HW_S390_PV_H */
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index a89cf4c129..f718cfc591 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -41,6 +41,8 @@
> #include "hw/qdev-properties.h"
> #include "hw/s390x/tod.h"
> #include "sysemu/sysemu.h"
> +#include "hw/s390x/pv.h"
> +#include <linux/kvm.h>
>
> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> {
> @@ -238,9 +240,11 @@ static void s390_create_sclpconsole(const char *type,
> Chardev *chardev)
> static void ccw_init(MachineState *machine)
> {
> int ret;
> + S390CcwMachineState *ms = S390_CCW_MACHINE(machine);
> VirtualCssBus *css_bus;
> DeviceState *dev;
>
> + ms->pv = false;
> s390_sclp_init();
> /* init memory + setup max page size. Required for the CPU model */
> s390_memory_init(machine->ram);
> @@ -316,10 +320,90 @@ static inline void s390_do_cpu_ipl(CPUState *cs,
> run_on_cpu_data arg)
> s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
> }
>
> +static void s390_machine_unprotect(S390CcwMachineState *ms)
> +{
> + CPUState *t;
> +
> + if (ms->pv) {
This is always the case. The check for ms->pv dropped (and if other
patches require this, it is to be handled in the caller).
> + s390_pv_vm_disable();
> + CPU_FOREACH(t) {
> + S390_CPU(t)->env.pv = false;
> + }
> + ms->pv = false;
> + }
> +}
> +
> +static int s390_machine_protect(S390CcwMachineState *ms)
> +{
> + CPUState *t;
> + int rc;
> +
> + /* Create SE VM */
> + rc = s390_pv_vm_enable();
> + if (rc) {
> + return rc;
> + }
> +
> + CPU_FOREACH(t) {
> + S390_CPU(t)->env.pv = true;
> + }
> + ms->pv = true;
> +
> + /* Set SE header and unpack */
> + rc = s390_ipl_prepare_pv_header();
> + if (rc) {
> + goto out_err;
> + }
> +
> + /* Decrypt image */
> + rc = s390_ipl_pv_unpack();
> + if (rc) {
> + goto out_err;
> + }
> +
> + /* Verify integrity */
> + rc = s390_pv_verify();
> + if (rc) {
> + goto out_err;
> + }
> + return rc;
> +
> +out_err:
> + s390_machine_unprotect(ms);
> + return rc;
> +}
> +
> +#define DIAG_308_RC_INVAL_FOR_PV 0x0a02
> +static void s390_machine_inject_pv_error(CPUState *cs)
> +{
> + int r1 = (cs->kvm_run->s390_sieic.ipa & 0x00f0) >> 4;
> + CPUS390XState *env = &S390_CPU(cs)->env;
> +
> + /* Report that we are unable to enter protected mode */
> + env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV;
> +}
> +
> +static void s390_pv_prepare_reset(CPUS390XState *env)
> +{
> + CPUState *cs;
> +
> + if (!env->pv) {
> + return;
> + }
> + CPU_FOREACH(cs) {
> + s390_cpu_set_state(S390_CPU_STATE_STOPPED, S390_CPU(cs));
> + }
This is done by the CPU reset in all cases? Why is that needed? (->comment)
> + s390_pv_unshare();
> + s390_pv_perf_clear_reset();
> +}
> +
> static void s390_machine_reset(MachineState *machine)
> {
> enum s390_reset reset_type;
> CPUState *cs, *t;
> + S390CPU *cpu;
> + S390CcwMachineState *ms = S390_CCW_MACHINE(machine);
Nit: Move this to the very top.
> + CPUS390XState *env;
>
> /* get the reset parameters, reset them once done */
> s390_ipl_get_reset_request(&cs, &reset_type);
> @@ -327,9 +411,16 @@ static void s390_machine_reset(MachineState *machine)
> /* all CPUs are paused and synchronized at this point */
> s390_cmma_reset();
>
> + cpu = S390_CPU(cs);
> + env = &cpu->env;
Can you just pass "cpu" to s390_pv_prepare_reset() and handle it in there?
> +
> switch (reset_type) {
> case S390_RESET_EXTERNAL:
> case S390_RESET_REIPL:
> + if (ms->pv) {
> + s390_machine_unprotect(ms);
> + }
> +
> qemu_devices_reset();
> s390_crypto_reset();
>
> @@ -337,22 +428,52 @@ static void s390_machine_reset(MachineState *machine)
> run_on_cpu(cs, s390_do_cpu_ipl, RUN_ON_CPU_NULL);
> break;
> case S390_RESET_MODIFIED_CLEAR:
> + /*
> + * Susbsystem reset needs to be done before we unshare memory
> + * and loose access to VIRTIO structures in guest memory.
> + */
> + subsystem_reset();
> + s390_crypto_reset();
> + s390_pv_prepare_reset(env);
> CPU_FOREACH(t) {
> run_on_cpu(t, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
> }
> - subsystem_reset();
> - s390_crypto_reset();
> run_on_cpu(cs, s390_do_cpu_load_normal, RUN_ON_CPU_NULL);
> break;
> case S390_RESET_LOAD_NORMAL:
> + /*
> + * Susbsystem reset needs to be done before we unshare memory
> + * and loose access to VIRTIO structures in guest memory.
> + */
> + subsystem_reset();
> + s390_pv_prepare_reset(env);
> CPU_FOREACH(t) {
> if (t == cs) {
> continue;
> }
> run_on_cpu(t, s390_do_cpu_reset, RUN_ON_CPU_NULL);
> }
> - subsystem_reset();
> run_on_cpu(cs, s390_do_cpu_initial_reset, RUN_ON_CPU_NULL);
> + run_on_cpu(cs, s390_do_cpu_load_normal, RUN_ON_CPU_NULL);
> + break;
> + case S390_RESET_PV: /* Subcode 10 */
> + subsystem_reset();
> + s390_crypto_reset();
> +
> + CPU_FOREACH(t) {
> + if (t == cs) {
> + continue;
> + }
> + run_on_cpu(t, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
> + }
> + run_on_cpu(cs, s390_do_cpu_reset, RUN_ON_CPU_NULL);
> +
> + if (s390_machine_protect(ms)) {
> + s390_machine_inject_pv_error(cs);
> + s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
> + return;
> + }
> +
> run_on_cpu(cs, s390_do_cpu_load_normal, RUN_ON_CPU_NULL);
[...]
>
> +#if !defined(CONFIG_USER_ONLY)
> +static bool machine_is_pv(MachineState *ms)
> +{
> + Object *obj;
> +
> + /* we have to bail out for the "none" machine */
> + obj = object_dynamic_cast(OBJECT(ms), TYPE_S390_CCW_MACHINE);
> + if (!obj) {
> + return false;
> + }
> + return S390_CCW_MACHINE(obj)->pv;
Maybe you want to cache the machine, so you can avoid the
lookup+conversion on every new CPU.
> +}
> +#endif
[...]
> static int diag308_parm_check(CPUS390XState *env, uint64_t r1, uint64_t addr,
> uintptr_t ra, bool write)
> {
> + /* Handled by the Ultravisor */
> + if (env->pv) {
> + return 0;
> + }
> if ((r1 & 1) || (addr & ~TARGET_PAGE_MASK)) {
> s390_program_interrupt(env, PGM_SPECIFICATION, ra);
> return -1;
> @@ -93,6 +101,11 @@ void handle_diag_308(CPUS390XState *env, uint64_t r1,
> uint64_t r3, uintptr_t ra)
> return;
> }
>
> + if (subcode > 7 && !s390_has_feat(S390_FEAT_UNPACK)) {
>= DIAG308_PV_SET
> + s390_program_interrupt(env, PGM_SPECIFICATION, ra);
> + return;
> + }
> +
--
Thanks,
David / dhildenb
