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From: Nicholas Piggin <npiggin@gmail.com>
To: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH 11/13] KVM: PPC: Book3S HV: Minimise hcall handler calling convention differences
Date: Fri, 19 Feb 2021 16:35:40 +1000	[thread overview]
Message-ID: <20210219063542.1425130-12-npiggin@gmail.com> (raw)
In-Reply-To: <20210219063542.1425130-1-npiggin@gmail.com>

This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.

This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 16 +++++++++++++++-
 arch/powerpc/kvm/book3s_64_entry.S   | 22 +++-------------------
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 4878f05b5325..6f086ee922e0 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1923,8 +1923,22 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
 
 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 TRAMP_REAL_BEGIN(kvm_hcall)
+	std	r9,PACA_EXGEN+EX_R9(r13)
+	std	r11,PACA_EXGEN+EX_R11(r13)
+	std	r12,PACA_EXGEN+EX_R12(r13)
+	mfcr	r9
 	mfctr	r10
-	SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
+	std	r10,PACA_EXGEN+EX_R13(r13)
+	li	r10,0
+	std	r10,PACA_EXGEN+EX_CFAR(r13)
+	std	r10,PACA_EXGEN+EX_CTR(r13)
+BEGIN_FTR_SECTION
+	mfspr	r10,SPRN_PPR
+	std	r10,PACA_EXGEN+EX_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+	HMT_MEDIUM
+
 #ifdef CONFIG_RELOCATABLE
 	/*
 	 * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 6b2fda5dee38..6f06b58b1bdd 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -13,24 +13,9 @@
 .global	kvmppc_hcall
 .balign IFETCH_ALIGN_BYTES
 kvmppc_hcall:
-	/*
-	 * This is a hcall, so register convention is as
-	 * Documentation/powerpc/papr_hcalls.rst, with these additions:
-	 * R13		= PACA
-	 * guest R13 saved in SPRN_SCRATCH0
-	 * R10		= free
-	 */
-BEGIN_FTR_SECTION
-	mfspr	r10,SPRN_PPR
-	std	r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
-	HMT_MEDIUM
-	mfcr	r10
-	std	r12,HSTATE_SCRATCH0(r13)
-	sldi	r12,r10,32
-	ori	r12,r12,0xc00
-	ld	r10,PACA_EXGEN+EX_R10(r13)
-	b	do_kvm_interrupt
+	ld	r10,PACA_EXGEN+EX_R13(r13)
+	SET_SCRATCH0(r10)
+	li	r10,0xc00
 
 .global	kvmppc_interrupt
 .balign IFETCH_ALIGN_BYTES
@@ -61,7 +46,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 	ld	r10,EX_R10(r11)
 	ld	r11,EX_R11(r11)
 
-do_kvm_interrupt:
 	/*
 	 * Hcalls and other interrupts come here after normalising register
 	 * contents and save locations:
-- 
2.23.0


  parent reply	other threads:[~2021-02-19  6:41 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-19  6:35 [PATCH 00/13] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin
2021-02-19  6:35 ` [PATCH 01/13] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts Nicholas Piggin
2021-02-22 22:22   ` Fabiano Rosas
2021-02-19  6:35 ` [PATCH 02/13] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Nicholas Piggin
2021-02-22 22:22   ` Fabiano Rosas
2021-02-19  6:35 ` [PATCH 03/13] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR Nicholas Piggin
2021-02-22 22:23   ` Fabiano Rosas
2021-02-19  6:35 ` [PATCH 04/13] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument Nicholas Piggin
2021-02-19  6:35 ` [PATCH 05/13] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point Nicholas Piggin
2021-02-19  6:35 ` [PATCH 06/13] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM Nicholas Piggin
2021-02-22 22:40   ` Fabiano Rosas
2021-02-19  6:35 ` [PATCH 07/13] KVM: PPC: Book3S 64: add hcall interrupt handler Nicholas Piggin
2021-02-19  6:35 ` [PATCH 08/13] KVM: PPC: Book3S HV: Move hcall early register setup to KVM Nicholas Piggin
2021-02-19  6:35 ` [PATCH 09/13] KVM: PPC: Book3S HV: Move interrupt " Nicholas Piggin
2021-02-19  6:35 ` [PATCH 10/13] KVM: PPC: Book3S HV: move bad_host_intr check to HV handler Nicholas Piggin
2021-02-19  6:35 ` Nicholas Piggin [this message]
2021-02-19  6:35 ` [PATCH 12/13] KVM: PPC: Book3S HV: Move radix MMU switching together in the P9 path Nicholas Piggin
2021-02-24 20:36   ` Fabiano Rosas
2021-02-25 10:59     ` Nicholas Piggin
2021-02-19  6:35 ` [PATCH 13/13] KVM: PPC: Book3S HV: Implement the rest of the P9 entry/exit handling in C Nicholas Piggin

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