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target/arm: do not use cc->do_interrupt for KVM directly 

cc->do_interrupt is in theory a TCG callback used in accel/tcg only,
to prepare the emulated architecture to take an interrupt as defined
in the hardware specifications,

but in reality the _do_interrupt style of functions in targets are
also occasionally reused by KVM to prepare the architecture state in a
similar way where userspace code has identified that it needs to
deliver an exception to the guest.

In the case of ARM, that includes:

1) the vcpu thread got a SIGBUS indicating a memory error,
   and we need to deliver a Synchronous External Abort to the guest to
   let it know about the error.
2) the kernel told us about a debug exception (breakpoint, watchpoint)
   but it is not for one of QEMU's own gdbstub breakpoints/watchpoints
   so it must be a breakpoint the guest itself has set up, therefore
   we need to deliver it to the guest.

So in order to reuse code, the same arm_do_interrupt function is used.
This is all fine, but we need to avoid calling it using the callback
registered in CPUClass, since that one is now TCG-only.

Fortunately this is easily solved by replacing calls to
CPUClass::do_interrupt() with explicit calls to arm_do_interrupt().

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210204163931.7358-9-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Claudio Fontana 2021-02-04 17:39:16 +01:00 committed by Richard Henderson
parent e9ce43e97a
commit 853bfef4e6
2 changed files with 6 additions and 4 deletions
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4
target/arm/helper.c
View File

@ -9969,6 +9969,10 @@ static void handle_semihosting(CPUState *cs)
* Do any appropriate logging, handle PSCI calls, and then hand off
* to the AArch64-entry or AArch32-entry function depending on the
* target exception level's register width.
*
* Note: this is used for both TCG (as the do_interrupt tcg op),
* and KVM to re-inject guest debug exceptions, and to
* inject a Synchronous-External-Abort.
*/
void arm_cpu_do_interrupt(CPUState *cs)
{

6
target/arm/kvm64.c
View File

@ -946,7 +946,6 @@ static void kvm_inject_arm_sea(CPUState *c)
{
ARMCPU *cpu = ARM_CPU(c);
CPUARMState *env = &cpu->env;
CPUClass *cc = CPU_GET_CLASS(c);
uint32_t esr;
bool same_el;
@ -962,7 +961,7 @@ static void kvm_inject_arm_sea(CPUState *c)
env->exception.syndrome = esr;
cc->do_interrupt(c);
arm_cpu_do_interrupt(c);
}
#define AARCH64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \
@ -1493,7 +1492,6 @@ bool kvm_arm_handle_debug(CPUState *cs, struct kvm_debug_exit_arch *debug_exit)
{
int hsr_ec = syn_get_ec(debug_exit->hsr);
ARMCPU *cpu = ARM_CPU(cs);
CPUClass *cc = CPU_GET_CLASS(cs);
CPUARMState *env = &cpu->env;
/* Ensure PC is synchronised */
@ -1547,7 +1545,7 @@ bool kvm_arm_handle_debug(CPUState *cs, struct kvm_debug_exit_arch *debug_exit)
env->exception.vaddress = debug_exit->far;
env->exception.target_el = 1;
qemu_mutex_lock_iothread();
cc->do_interrupt(cs);
arm_cpu_do_interrupt(cs);
qemu_mutex_unlock_iothread();
return false;