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Re: [Xen-devel] [PATCH v6 07/10] arm: traps: handle PSCI calls inside `vsmc.c`
Hi Volodymyr,
On 21/09/17 21:00, Volodymyr Babchuk wrote:
PSCI is part of HVC/SMC interface, so it should be handled in
appropriate place: `vsmc.c`. This patch moves PSCI handler
calls from `traps.c` to `vsmc.c`. Also it corrects coding
style of the PSCI handler functions.
Older PSCI 0.1 uses SMC function identifiers in range that is
reserved for existing APIs (ARM DEN 0028B, page 16), while newer
PSCI 0.2 and later is defined as "standard secure service" with its
own ranges (ARM DEN 0028B, page 18).
Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@xxxxxxxx>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
---
* Fixed aligning of SSSC_SMCCC_UID XEN_DEFINE_UUID()
* Fixed compilation bug. Previous version used inlined function
smccc_get_fn() in 'case' statement. That was artifact of refactoring, because
I was asked to replace macroses in asm-arm/smccc.h to inlined functions.
But, apparently, you can't write `case func():`.
Next patched fixed this problem anyways. But anyways...
* Removed call to PSCI_ARG32() from handle_existing_apis()
* Used newly added helper functions
---
xen/arch/arm/traps.c | 117 +----------------------
xen/arch/arm/vsmc.c | 183 +++++++++++++++++++++++++++++++++++-
xen/include/asm-arm/traps.h | 1 +
xen/include/public/arch-arm/smccc.h | 8 ++
4 files changed, 190 insertions(+), 119 deletions(-)
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 8397188..61980ea 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1452,119 +1452,6 @@ static void do_debug_trap(struct cpu_user_regs *regs,
unsigned int code)
}
#endif
-#define PSCI_SET_RESULT(reg, val) set_user_reg(reg, 0, val)
-#define PSCI_ARG(reg,n) get_user_reg(reg, n)
-
-#ifdef CONFIG_ARM_64
-#define PSCI_ARG32(reg,n) (uint32_t)get_user_reg(reg,n)
-#else
-#define PSCI_ARG32(reg,n) PSCI_ARG(reg,n)
-#endif
-
-/* helper function for checking arm mode 32/64 bit */
-static inline int psci_mode_check(struct domain *d, register_t fid)
-{
- return !( is_64bit_domain(d)^( (fid & PSCI_0_2_64BIT) >> 30 ) );
-}
-
-static void do_trap_psci(struct cpu_user_regs *regs)
-{
- register_t fid = PSCI_ARG(regs,0);
-
- /* preloading in case psci_mode_check fails */
- PSCI_SET_RESULT(regs, PSCI_INVALID_PARAMETERS);
- switch( fid )
- {
- case PSCI_cpu_off:
- {
- uint32_t pstate = PSCI_ARG32(regs,1);
- perfc_incr(vpsci_cpu_off);
- PSCI_SET_RESULT(regs, do_psci_cpu_off(pstate));
- }
- break;
- case PSCI_cpu_on:
- {
- uint32_t vcpuid = PSCI_ARG32(regs,1);
- register_t epoint = PSCI_ARG(regs,2);
- perfc_incr(vpsci_cpu_on);
- PSCI_SET_RESULT(regs, do_psci_cpu_on(vcpuid, epoint));
- }
- break;
- case PSCI_0_2_FN_PSCI_VERSION:
- perfc_incr(vpsci_version);
- PSCI_SET_RESULT(regs, do_psci_0_2_version());
- break;
- case PSCI_0_2_FN_CPU_OFF:
- perfc_incr(vpsci_cpu_off);
- PSCI_SET_RESULT(regs, do_psci_0_2_cpu_off());
- break;
- case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
- perfc_incr(vpsci_migrate_info_type);
- PSCI_SET_RESULT(regs, do_psci_0_2_migrate_info_type());
- break;
- case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
- case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
- perfc_incr(vpsci_migrate_info_up_cpu);
- if ( psci_mode_check(current->domain, fid) )
- PSCI_SET_RESULT(regs, do_psci_0_2_migrate_info_up_cpu());
- break;
- case PSCI_0_2_FN_SYSTEM_OFF:
- perfc_incr(vpsci_system_off);
- do_psci_0_2_system_off();
- PSCI_SET_RESULT(regs, PSCI_INTERNAL_FAILURE);
- break;
- case PSCI_0_2_FN_SYSTEM_RESET:
- perfc_incr(vpsci_system_reset);
- do_psci_0_2_system_reset();
- PSCI_SET_RESULT(regs, PSCI_INTERNAL_FAILURE);
- break;
- case PSCI_0_2_FN_CPU_ON:
- case PSCI_0_2_FN64_CPU_ON:
- perfc_incr(vpsci_cpu_on);
- if ( psci_mode_check(current->domain, fid) )
- {
- register_t vcpuid = PSCI_ARG(regs,1);
- register_t epoint = PSCI_ARG(regs,2);
- register_t cid = PSCI_ARG(regs,3);
- PSCI_SET_RESULT(regs, do_psci_0_2_cpu_on(vcpuid, epoint, cid));
- }
- break;
- case PSCI_0_2_FN_CPU_SUSPEND:
- case PSCI_0_2_FN64_CPU_SUSPEND:
- perfc_incr(vpsci_cpu_suspend);
- if ( psci_mode_check(current->domain, fid) )
- {
- uint32_t pstate = PSCI_ARG32(regs,1);
- register_t epoint = PSCI_ARG(regs,2);
- register_t cid = PSCI_ARG(regs,3);
- PSCI_SET_RESULT(regs, do_psci_0_2_cpu_suspend(pstate, epoint,
cid));
- }
- break;
- case PSCI_0_2_FN_AFFINITY_INFO:
- case PSCI_0_2_FN64_AFFINITY_INFO:
- perfc_incr(vpsci_cpu_affinity_info);
- if ( psci_mode_check(current->domain, fid) )
- {
- register_t taff = PSCI_ARG(regs,1);
- uint32_t laff = PSCI_ARG32(regs,2);
- PSCI_SET_RESULT(regs, do_psci_0_2_affinity_info(taff, laff));
- }
- break;
- case PSCI_0_2_FN_MIGRATE:
- case PSCI_0_2_FN64_MIGRATE:
- perfc_incr(vpsci_cpu_migrate);
- if ( psci_mode_check(current->domain, fid) )
- {
- uint32_t tcpu = PSCI_ARG32(regs,1);
- PSCI_SET_RESULT(regs, do_psci_0_2_migrate(tcpu));
- }
- break;
- default:
- domain_crash_synchronous();
- return;
- }
-}
-
#ifdef CONFIG_ARM_64
#define HYPERCALL_RESULT_REG(r) (r)->x0
#define HYPERCALL_ARG1(r) (r)->x0
@@ -2270,7 +2157,7 @@ void do_trap_guest_sync(struct cpu_user_regs *regs)
return do_debug_trap(regs, hsr.iss & 0x00ff);
#endif
if ( hsr.iss == 0 )
- return do_trap_psci(regs);
+ return do_trap_hvc_smccc(regs);
do_trap_hypercall(regs, (register_t *)®s->r12, hsr.iss);
break;
#ifdef CONFIG_ARM_64
@@ -2282,7 +2169,7 @@ void do_trap_guest_sync(struct cpu_user_regs *regs)
return do_debug_trap(regs, hsr.iss & 0x00ff);
#endif
if ( hsr.iss == 0 )
- return do_trap_psci(regs);
+ return do_trap_hvc_smccc(regs);
do_trap_hypercall(regs, ®s->x16, hsr.iss);
break;
case HSR_EC_SMC64:
diff --git a/xen/arch/arm/vsmc.c b/xen/arch/arm/vsmc.c
index 38df821..6ab7c55 100644
--- a/xen/arch/arm/vsmc.c
+++ b/xen/arch/arm/vsmc.c
@@ -19,6 +19,7 @@
#include <xen/types.h>
#include <public/arch-arm/smccc.h>
#include <asm/monitor.h>
+#include <asm/psci.h>
#include <asm/regs.h>
#include <asm/smccc.h>
#include <asm/traps.h>
@@ -26,6 +27,9 @@
/* Number of functions currently supported by Hypervisor Service. */
#define XEN_SMCCC_FUNCTION_COUNT 3
+/* Number of functions currently supported by Standard Service Service Calls. */
+#define SSSC_SMCCC_FUNCTION_COUNT 13
+
static bool fill_uid(struct cpu_user_regs *regs, xen_uuid_t uuid)
{
int n;
@@ -94,6 +98,148 @@ static bool handle_hypervisor(struct cpu_user_regs *regs)
}
}
+#define PSCI_SET_RESULT(reg, val) set_user_reg(reg, 0, val)
+#define PSCI_ARG(reg, n) get_user_reg(reg, n)
+
+#ifdef CONFIG_ARM_64
+#define PSCI_ARG32(reg, n) (uint32_t)(get_user_reg(reg, n))
+#else
+#define PSCI_ARG32(reg, n) PSCI_ARG(reg, n)
+#endif
+
+/* Existing (pre SMCCC) APIs. This includes PSCI 0.1 interface */
+static bool handle_existing_apis(struct cpu_user_regs *regs)
+{
+ switch ( get_user_reg(regs, 0) )
+ {
+ case PSCI_cpu_off:
+ {
+ uint32_t pstate = PSCI_ARG32(regs, 1);
+
+ perfc_incr(vpsci_cpu_off);
+ PSCI_SET_RESULT(regs, do_psci_cpu_off(pstate));
+ return true;
+ }
+ case PSCI_cpu_on:
+ {
+ uint32_t vcpuid = PSCI_ARG32(regs, 1);
+ register_t epoint = PSCI_ARG(regs, 2);
+
+ perfc_incr(vpsci_cpu_on);
+ PSCI_SET_RESULT(regs, do_psci_cpu_on(vcpuid, epoint));
+ return true;
+ }
+ default:
+ return false;
+ }
+}
+
+/* helper function for checking arm mode 32/64 bit */
+static inline int psci_mode_check(struct domain *d, register_t fid)
+{
+ return !( is_64bit_domain(d)^( (fid & PSCI_0_2_64BIT) >> 30 ) );
+}
+
+/* PSCI 0.2 interface and other Standard Secure Calls */
+static bool handle_sssc(struct cpu_user_regs *regs)
+{
+ register_t fid = PSCI_ARG(regs, 0);
I know I only made a comment on handle_existing_apis about PSCI_ARG32 in
the previous version. The comment is always applying here.
However, you seemed to have assumed that you could drop PSCI_ARG32(...)
and left my question unanswered.
My question was legitimate to know why in one place you were using
32-bit and the other 32-bit for the function ID.
If you look at the spec (section 3.1), the function identifier is using
w0 and you should ignore the 32-bit most significants bits.
Note that this bug is already present in the current implementation. It
might be worth to prepend a patch to this series for fixing the code so
we could also backport it.
+
+ switch ( fid )
+ {
+ case PSCI_0_2_FN_PSCI_VERSION:
+ perfc_incr(vpsci_version);
+ PSCI_SET_RESULT(regs, do_psci_0_2_version());
+ return true;
+
+ case PSCI_0_2_FN_CPU_OFF:
+ perfc_incr(vpsci_cpu_off);
+ PSCI_SET_RESULT(regs, do_psci_0_2_cpu_off());
+ return true;
+
+ case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
+ perfc_incr(vpsci_migrate_info_type);
+ PSCI_SET_RESULT(regs, do_psci_0_2_migrate_info_type());
+ return true;
+
+ case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
+ perfc_incr(vpsci_migrate_info_up_cpu);
+ if ( psci_mode_check(current->domain, fid) )
+ PSCI_SET_RESULT(regs, do_psci_0_2_migrate_info_up_cpu());
+ return true;
+
+ case PSCI_0_2_FN_SYSTEM_OFF:
+ perfc_incr(vpsci_system_off);
+ do_psci_0_2_system_off();
+ PSCI_SET_RESULT(regs, PSCI_INTERNAL_FAILURE);
+ return true;
+
+ case PSCI_0_2_FN_SYSTEM_RESET:
+ perfc_incr(vpsci_system_reset);
+ do_psci_0_2_system_reset();
+ PSCI_SET_RESULT(regs, PSCI_INTERNAL_FAILURE);
+ return true;
+
+ case PSCI_0_2_FN_CPU_ON:
+ perfc_incr(vpsci_cpu_on);
+ if ( psci_mode_check(current->domain, fid) )
+ {
+ register_t vcpuid = PSCI_ARG(regs, 1);
+ register_t epoint = PSCI_ARG(regs, 2);
+ register_t cid = PSCI_ARG(regs, 3);
+
+ PSCI_SET_RESULT(regs, do_psci_0_2_cpu_on(vcpuid, epoint, cid));
+ }
+ return true;
+
+ case PSCI_0_2_FN_CPU_SUSPEND:
+ perfc_incr(vpsci_cpu_suspend);
+ if ( psci_mode_check(current->domain, fid) )
+ {
+ uint32_t pstate = PSCI_ARG32(regs, 1);
+ register_t epoint = PSCI_ARG(regs, 2);
+ register_t cid = PSCI_ARG(regs, 3);
+
+ PSCI_SET_RESULT(regs, do_psci_0_2_cpu_suspend(pstate, epoint,
cid));
+ }
+ return true;
+
+ case PSCI_0_2_FN_AFFINITY_INFO:
+ perfc_incr(vpsci_cpu_affinity_info);
+ if ( psci_mode_check(current->domain, fid) )
+ {
+ register_t taff = PSCI_ARG(regs, 1);
+ uint32_t laff = PSCI_ARG32(regs, 2);
+ PSCI_SET_RESULT(regs, do_psci_0_2_affinity_info(taff, laff));
+ }
+ return true;
+
+ case PSCI_0_2_FN_MIGRATE:
+ perfc_incr(vpsci_cpu_migrate);
+ if ( psci_mode_check(current->domain, fid) )
+ {
+ uint32_t tcpu = PSCI_ARG32(regs, 1);
+
+ PSCI_SET_RESULT(regs, do_psci_0_2_migrate(tcpu));
+ }
+ return true;
+
+ case ARM_SMCCC_FUNC_CALL_COUNT:
+ return fill_function_call_count(regs, SSSC_SMCCC_FUNCTION_COUNT);
+ return true;
The return true is not necessary here.
+
+ case ARM_SMCCC_FUNC_CALL_UID:
+ return fill_uid(regs, SSSC_SMCCC_UID);
+
+ case ARM_SMCCC_FUNC_CALL_REVISION:
+ return fill_revision(regs, SSSC_SMCCC_MAJOR_REVISION,
+ SSSC_SMCCC_MINOR_REVISION);
+
+ default:
+ return false;
+ }
+}
+
/*
* vsmccc_handle_call() - handle SMC/HVC call according to ARM SMCCC.
* returns true if that was valid SMCCC call (even if function number
@@ -133,11 +279,26 @@ static bool vsmccc_handle_call(struct cpu_user_regs *regs)
return true;
}
- switch ( smccc_get_owner(funcid) )
+ /*
+ * Special case: identifier range for existing APIs.
+ * This range is described in SMCCC (ARM DEN 0028B, page 16),
+ * but it does not conforms to standard function identifier
+ * encoding.
+ */
+ if ( funcid >= ARM_SMCCC_RESERVED_RANGE_START &&
+ funcid <= ARM_SMCCC_RESERVED_RANGE_END )
+ handled = handle_existing_apis(regs);
+ else
{
- case ARM_SMCCC_OWNER_HYPERVISOR:
- handled = handle_hypervisor(regs);
- break;
+ switch ( smccc_get_owner(funcid) )
+ {
+ case ARM_SMCCC_OWNER_HYPERVISOR:
+ handled = handle_hypervisor(regs);
+ break;
+ case ARM_SMCCC_OWNER_STANDARD:
+ handled = handle_sssc(regs);
+ break;
+ }
}
if ( !handled )
@@ -181,6 +342,20 @@ void do_trap_smc(struct cpu_user_regs *regs, const union
hsr hsr)
inject_undef_exception(regs, hsr);
}
+void do_trap_hvc_smccc(struct cpu_user_regs *regs)
+{
+ const union hsr hsr = { .bits = regs->hsr };
+
+ /*
+ * vsmccc_handle_call() will return false if this call is not
+ * SMCCC compatible (e.g. immediate value != 0). As it is not
+ * compatible, we can't be sure that guest will understand
+ * ARM_SMCCC_ERR_UNKNOWN_FUNCTION.
+ */
+ if ( !vsmccc_handle_call(regs) )
+ inject_undef_exception(regs, hsr);
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/include/asm-arm/traps.h b/xen/include/asm-arm/traps.h
index 6efd1c5..0b91aa7 100644
--- a/xen/include/asm-arm/traps.h
+++ b/xen/include/asm-arm/traps.h
@@ -33,6 +33,7 @@ void do_cp(struct cpu_user_regs *regs, const union hsr hsr);
/* SMCCC handling */
void do_trap_smc(struct cpu_user_regs *regs, const union hsr hsr);
+void do_trap_hvc_smccc(struct cpu_user_regs *regs);
#endif /* __ASM_ARM_TRAPS__ */
/*
diff --git a/xen/include/public/arch-arm/smccc.h
b/xen/include/public/arch-arm/smccc.h
index 2bee5b3..17dc6d8 100644
--- a/xen/include/public/arch-arm/smccc.h
+++ b/xen/include/public/arch-arm/smccc.h
@@ -46,6 +46,14 @@
#define XEN_SMCCC_UID XEN_DEFINE_UUID(0xa71812dc, 0xc698, 0x4369, 0x9acf, \
0x79, 0xd1, 0x8d, 0xde, 0xe6, 0x67)
+/* Standard Service Service Call version. */
+#define SSSC_SMCCC_MAJOR_REVISION 0
+#define SSSC_SMCCC_MINOR_REVISION 1
+
+/* Standard Service Call UID. Randomly generated with uuidgen. */
+#define SSSC_SMCCC_UID XEN_DEFINE_UUID(0xf863386f, 0x4b39, 0x4cbd, 0x9220,\
+ 0xce, 0x16, 0x41, 0xe5, 0x9f, 0x6f)
+
#endif /* __XEN_PUBLIC_ARCH_ARM_SMCCC_H__ */
/*
Cheers,
--
Julien Grall
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