This streamlines the first part of the code that handles a hypervisor
interrupt that occurred in the guest. With this, all of the real-mode
handling that occurs is done before the "guest_exit_cont" label; once
we get to that label we are committed to exiting to host virtual mode.
Thus the machine check and HMI real-mode handling is moved before that
label.
Also, the code to handle external interrupts is moved out of line, as
is the code that calls kvmppc_realmode_hmi_handler().
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv_ras.c | 8 ++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 220 ++++++++++++++++----------------
2 files changed, 119 insertions(+), 109 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_ras.c b/arch/powerpc/kvm/book3s_hv_ras.c
index b11043b..ee564b6 100644
--- a/arch/powerpc/kvm/book3s_hv_ras.c
+++ b/arch/powerpc/kvm/book3s_hv_ras.c
@@ -331,5 +331,13 @@ long kvmppc_realmode_hmi_handler(void)
} else {
wait_for_tb_resync();
}
+
+ /*
+ * Reset tb_offset_applied so the guest exit code won't try
+ * to subtract the previous timebase offset from the timebase.
+ */
+ if (local_paca->kvm_hstate.kvm_vcore)
+ local_paca->kvm_hstate.kvm_vcore->tb_offset_applied = 0;
+
return 0;
}
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5b2ae34..772740d 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1018,8 +1018,7 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
no_xive:
#endif /* CONFIG_KVM_XICS */
-deliver_guest_interrupt:
-kvmppc_cede_reentry: /* r4 = vcpu, r13 = paca */
+deliver_guest_interrupt: /* r4 = vcpu, r13 = paca */
/* Check if we can deliver an external or decrementer interrupt now */
ld r0, VCPU_PENDING_EXC(r4)
BEGIN_FTR_SECTION
@@ -1269,18 +1268,26 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
std r3, VCPU_CTR(r9)
std r4, VCPU_XER(r9)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
- /* For softpatch interrupt, go off and do TM instruction emulation */
- cmpwi r12, BOOK3S_INTERRUPT_HV_SOFTPATCH
- beq kvmppc_tm_emul
-#endif
+ /* Save more register state */
+ mfdar r6
+ mfdsisr r7
+ std r6, VCPU_DAR(r9)
+ stw r7, VCPU_DSISR(r9)
/* If this is a page table miss then see if it's theirs or ours */
cmpwi r12, BOOK3S_INTERRUPT_H_DATA_STORAGE
beq kvmppc_hdsi
+ std r6, VCPU_FAULT_DAR(r9)
+ stw r7, VCPU_FAULT_DSISR(r9)
cmpwi r12, BOOK3S_INTERRUPT_H_INST_STORAGE
beq kvmppc_hisi
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ /* For softpatch interrupt, go off and do TM instruction emulation */
+ cmpwi r12, BOOK3S_INTERRUPT_HV_SOFTPATCH
+ beq kvmppc_tm_emul
+#endif
+
/* See if this is a leftover HDEC interrupt */
cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER
bne 2f
@@ -1303,7 +1310,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
lbz r0, HSTATE_HOST_IPI(r13)
cmpwi r0, 0
- beq 4f
+ beq maybe_reenter_guest
b guest_exit_cont
3:
/* If it's a hypervisor facility unavailable interrupt, save HFSCR */
@@ -1315,82 +1322,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
14:
/* External interrupt ? */
cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
- bne+ guest_exit_cont
-
- /* External interrupt, first check for host_ipi. If this is
- * set, we know the host wants us out so let's do it now
- */
- bl kvmppc_read_intr
-
- /*
- * Restore the active volatile registers after returning from
- * a C function.
- */
- ld r9, HSTATE_KVM_VCPU(r13)
- li r12, BOOK3S_INTERRUPT_EXTERNAL
-
- /*
- * kvmppc_read_intr return codes:
- *
- * Exit to host (r3 > 0)
- * 1 An interrupt is pending that needs to be handled by the host
- * Exit guest and return to host by branching to guest_exit_cont
- *
- * 2 Passthrough that needs completion in the host
- * Exit guest and return to host by branching to guest_exit_cont
- * However, we also set r12 to BOOK3S_INTERRUPT_HV_RM_HARD
- * to indicate to the host to complete handling the interrupt
- *
- * Before returning to guest, we check if any CPU is heading out
- * to the host and if so, we head out also. If no CPUs are heading
- * check return values <= 0.
- *
- * Return to guest (r3 <= 0)
- * 0 No external interrupt is pending
- * -1 A guest wakeup IPI (which has now been cleared)
- * In either case, we return to guest to deliver any pending
- * guest interrupts.
- *
- * -2 A PCI passthrough external interrupt was handled
- * (interrupt was delivered directly to guest)
- * Return to guest to deliver any pending guest interrupts.
- */
-
- cmpdi r3, 1
- ble 1f
-
- /* Return code = 2 */
- li r12, BOOK3S_INTERRUPT_HV_RM_HARD
- stw r12, VCPU_TRAP(r9)
- b guest_exit_cont
-
-1: /* Return code <= 1 */
- cmpdi r3, 0
- bgt guest_exit_cont
-
- /* Return code <= 0 */
-4: ld r5, HSTATE_KVM_VCORE(r13)
- lwz r0, VCORE_ENTRY_EXIT(r5)
- cmpwi r0, 0x100
- mr r4, r9
- blt deliver_guest_interrupt
-
-guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
- /* Save more register state */
- mfdar r6
- mfdsisr r7
- std r6, VCPU_DAR(r9)
- stw r7, VCPU_DSISR(r9)
- /* don't overwrite fault_dar/fault_dsisr if HDSI */
- cmpwi r12,BOOK3S_INTERRUPT_H_DATA_STORAGE
- beq mc_cont
- std r6, VCPU_FAULT_DAR(r9)
- stw r7, VCPU_FAULT_DSISR(r9)
-
+ beq kvmppc_guest_external
/* See if it is a machine check */
cmpwi r12, BOOK3S_INTERRUPT_MACHINE_CHECK
beq machine_check_realmode
-mc_cont:
+ /* Or a hypervisor maintenance interrupt */
+ cmpwi r12, BOOK3S_INTERRUPT_HMI
+ beq hmi_realmode
+
+guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
+
#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
addi r3, r9, VCPU_TB_RMEXIT
mr r4, r9
@@ -1821,24 +1762,6 @@ BEGIN_FTR_SECTION
mtspr SPRN_DPDES, r8
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
- /* If HMI, call kvmppc_realmode_hmi_handler() */
- lwz r12, STACK_SLOT_TRAP(r1)
- cmpwi r12, BOOK3S_INTERRUPT_HMI
- bne 27f
- bl kvmppc_realmode_hmi_handler
- nop
- cmpdi r3, 0
- /*
- * At this point kvmppc_realmode_hmi_handler may have resync-ed
- * the TB, and if it has, we must not subtract the guest timebase
- * offset from the timebase. So, skip it.
- *
- * Also, do not call kvmppc_subcore_exit_guest() because it has
- * been invoked as part of kvmppc_realmode_hmi_handler().
- */
- beq 30f
-
-27:
/* Subtract timebase offset from timebase */
ld r8, VCORE_TB_OFFSET_APPL(r5)
cmpdi r8,0
@@ -1856,7 +1779,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
addis r8,r8,0x100 /* if so, increment upper 40 bits */
mtspr SPRN_TBU40,r8
-17: bl kvmppc_subcore_exit_guest
+17:
+ /*
+ * If this is an HMI, we called kvmppc_realmode_hmi_handler
+ * above, which may or may not have already called
+ * kvmppc_subcore_exit_guest. Fortunately, all that
+ * kvmppc_subcore_exit_guest does is clear a flag, so calling
+ * it again here is benign even if kvmppc_realmode_hmi_handler
+ * has already called it.
+ */
+ bl kvmppc_subcore_exit_guest
nop
30: ld r5,HSTATE_KVM_VCORE(r13)
ld r4,VCORE_KVM(r5) /* pointer to struct kvm */
@@ -1910,6 +1842,67 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
mtlr r0
blr
+kvmppc_guest_external:
+ /* External interrupt, first check for host_ipi. If this is
+ * set, we know the host wants us out so let's do it now
+ */
+ bl kvmppc_read_intr
+
+ /*
+ * Restore the active volatile registers after returning from
+ * a C function.
+ */
+ ld r9, HSTATE_KVM_VCPU(r13)
+ li r12, BOOK3S_INTERRUPT_EXTERNAL
+
+ /*
+ * kvmppc_read_intr return codes:
+ *
+ * Exit to host (r3 > 0)
+ * 1 An interrupt is pending that needs to be handled by the host
+ * Exit guest and return to host by branching to guest_exit_cont
+ *
+ * 2 Passthrough that needs completion in the host
+ * Exit guest and return to host by branching to guest_exit_cont
+ * However, we also set r12 to BOOK3S_INTERRUPT_HV_RM_HARD
+ * to indicate to the host to complete handling the interrupt
+ *
+ * Before returning to guest, we check if any CPU is heading out
+ * to the host and if so, we head out also. If no CPUs are heading
+ * check return values <= 0.
+ *
+ * Return to guest (r3 <= 0)
+ * 0 No external interrupt is pending
+ * -1 A guest wakeup IPI (which has now been cleared)
+ * In either case, we return to guest to deliver any pending
+ * guest interrupts.
+ *
+ * -2 A PCI passthrough external interrupt was handled
+ * (interrupt was delivered directly to guest)
+ * Return to guest to deliver any pending guest interrupts.
+ */
+
+ cmpdi r3, 1
+ ble 1f
+
+ /* Return code = 2 */
+ li r12, BOOK3S_INTERRUPT_HV_RM_HARD
+ stw r12, VCPU_TRAP(r9)
+ b guest_exit_cont
+
+1: /* Return code <= 1 */
+ cmpdi r3, 0
+ bgt guest_exit_cont
+
+ /* Return code <= 0 */
+maybe_reenter_guest:
+ ld r5, HSTATE_KVM_VCORE(r13)
+ lwz r0, VCORE_ENTRY_EXIT(r5)
+ cmpwi r0, 0x100
+ mr r4, r9
+ blt deliver_guest_interrupt
+ b guest_exit_cont
+
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/*
* Softpatch interrupt for transactional memory emulation cases
@@ -2685,13 +2678,7 @@ END_FTR_SECTION(CPU_FTR_TM | CPU_FTR_P9_TM_HV_ASSIST, 0)
mr r9, r4
cmpdi r3, 0
bgt guest_exit_cont
-
- /* see if any other thread is already exiting */
- lwz r0,VCORE_ENTRY_EXIT(r5)
- cmpwi r0,0x100
- bge guest_exit_cont
-
- b kvmppc_cede_reentry /* if not go back to guest */
+ b maybe_reenter_guest
/* cede when already previously prodded case */
kvm_cede_prodded:
@@ -2758,12 +2745,12 @@ machine_check_realmode:
*/
ld r11, VCPU_MSR(r9)
rldicl. r0, r11, 64-MSR_HV_LG, 63 /* check if it happened in HV mode */
- bne mc_cont /* if so, exit to host */
+ bne guest_exit_cont /* if so, exit to host */
/* Check if guest is capable of handling NMI exit */
ld r10, VCPU_KVM(r9)
lbz r10, KVM_FWNMI(r10)
cmpdi r10, 1 /* FWNMI capable? */
- beq mc_cont /* if so, exit with KVM_EXIT_NMI. */
+ beq guest_exit_cont /* if so, exit with KVM_EXIT_NMI. */
/* if not, fall through for backward compatibility. */
andi. r10, r11, MSR_RI /* check for unrecoverable exception */
@@ -2777,6 +2764,21 @@ machine_check_realmode:
2: b fast_interrupt_c_return
/*
+ * Call C code to handle a HMI in real mode.
+ * Only the primary thread does the call, secondary threads are handled
+ * by calling hmi_exception_realmode() after kvmppc_hv_entry returns.
+ * r9 points to the vcpu on entry
+ */
+hmi_realmode:
+ lbz r0, HSTATE_PTID(r13)
+ cmpwi r0, 0
+ bne guest_exit_cont
+ bl kvmppc_realmode_hmi_handler
+ ld r9, HSTATE_KVM_VCPU(r13)
+ li r12, BOOK3S_INTERRUPT_HMI
+ b guest_exit_cont
+
+/*
* Check the reason we woke from nap, and take appropriate action.
* Returns (in r3):
* 0 if nothing needs to be done
--
2.7.4
