512ba59ed9
So far we've been restricting ourselves to r0-r29 as registers an mtmsr instruction could use. This was bad, as there are some code paths in Linux actually using r30. So let's instead handle all registers gracefully and get rid of that stupid limitation Signed-off-by: Alexander Graf <agraf@suse.de>
297 lines
7.0 KiB
ArmAsm
297 lines
7.0 KiB
ArmAsm
/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright SUSE Linux Products GmbH 2010
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*
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* Authors: Alexander Graf <agraf@suse.de>
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*/
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#include <asm/ppc_asm.h>
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#include <asm/kvm_asm.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/asm-offsets.h>
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/* Hypercall entry point. Will be patched with device tree instructions. */
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.global kvm_hypercall_start
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kvm_hypercall_start:
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li r3, -1
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nop
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nop
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nop
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blr
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#define KVM_MAGIC_PAGE (-4096)
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#ifdef CONFIG_64BIT
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#define LL64(reg, offs, reg2) ld reg, (offs)(reg2)
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#define STL64(reg, offs, reg2) std reg, (offs)(reg2)
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#else
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#define LL64(reg, offs, reg2) lwz reg, (offs + 4)(reg2)
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#define STL64(reg, offs, reg2) stw reg, (offs + 4)(reg2)
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#endif
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#define SCRATCH_SAVE \
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/* Enable critical section. We are critical if \
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shared->critical == r1 */ \
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STL64(r1, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0); \
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\
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/* Save state */ \
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PPC_STL r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0); \
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PPC_STL r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0); \
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mfcr r31; \
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stw r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);
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#define SCRATCH_RESTORE \
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/* Restore state */ \
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PPC_LL r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0); \
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lwz r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0); \
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mtcr r30; \
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PPC_LL r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0); \
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\
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/* Disable critical section. We are critical if \
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shared->critical == r1 and r2 is always != r1 */ \
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STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);
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.global kvm_emulate_mtmsrd
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kvm_emulate_mtmsrd:
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SCRATCH_SAVE
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/* Put MSR & ~(MSR_EE|MSR_RI) in r31 */
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LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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lis r30, (~(MSR_EE | MSR_RI))@h
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ori r30, r30, (~(MSR_EE | MSR_RI))@l
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and r31, r31, r30
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/* OR the register's (MSR_EE|MSR_RI) on MSR */
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kvm_emulate_mtmsrd_reg:
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andi. r30, r0, (MSR_EE|MSR_RI)
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or r31, r31, r30
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/* Put MSR back into magic page */
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STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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/* Check if we have to fetch an interrupt */
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lwz r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
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cmpwi r31, 0
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beq+ no_check
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/* Check if we may trigger an interrupt */
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andi. r30, r30, MSR_EE
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beq no_check
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SCRATCH_RESTORE
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/* Nag hypervisor */
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tlbsync
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b kvm_emulate_mtmsrd_branch
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no_check:
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SCRATCH_RESTORE
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/* Go back to caller */
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kvm_emulate_mtmsrd_branch:
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b .
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kvm_emulate_mtmsrd_end:
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.global kvm_emulate_mtmsrd_branch_offs
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kvm_emulate_mtmsrd_branch_offs:
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.long (kvm_emulate_mtmsrd_branch - kvm_emulate_mtmsrd) / 4
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.global kvm_emulate_mtmsrd_reg_offs
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kvm_emulate_mtmsrd_reg_offs:
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.long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4
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.global kvm_emulate_mtmsrd_len
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kvm_emulate_mtmsrd_len:
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.long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4
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#define MSR_SAFE_BITS (MSR_EE | MSR_CE | MSR_ME | MSR_RI)
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#define MSR_CRITICAL_BITS ~MSR_SAFE_BITS
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.global kvm_emulate_mtmsr
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kvm_emulate_mtmsr:
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SCRATCH_SAVE
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/* Fetch old MSR in r31 */
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LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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/* Find the changed bits between old and new MSR */
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kvm_emulate_mtmsr_reg1:
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ori r30, r0, 0
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xor r31, r30, r31
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/* Check if we need to really do mtmsr */
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LOAD_REG_IMMEDIATE(r30, MSR_CRITICAL_BITS)
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and. r31, r31, r30
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/* No critical bits changed? Maybe we can stay in the guest. */
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beq maybe_stay_in_guest
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do_mtmsr:
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SCRATCH_RESTORE
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/* Just fire off the mtmsr if it's critical */
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kvm_emulate_mtmsr_orig_ins:
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mtmsr r0
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b kvm_emulate_mtmsr_branch
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maybe_stay_in_guest:
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/* Get the target register in r30 */
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kvm_emulate_mtmsr_reg2:
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ori r30, r0, 0
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/* Check if we have to fetch an interrupt */
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lwz r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
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cmpwi r31, 0
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beq+ no_mtmsr
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/* Check if we may trigger an interrupt */
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andi. r31, r30, MSR_EE
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beq no_mtmsr
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b do_mtmsr
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no_mtmsr:
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/* Put MSR into magic page because we don't call mtmsr */
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STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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SCRATCH_RESTORE
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/* Go back to caller */
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kvm_emulate_mtmsr_branch:
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b .
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kvm_emulate_mtmsr_end:
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.global kvm_emulate_mtmsr_branch_offs
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kvm_emulate_mtmsr_branch_offs:
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.long (kvm_emulate_mtmsr_branch - kvm_emulate_mtmsr) / 4
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.global kvm_emulate_mtmsr_reg1_offs
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kvm_emulate_mtmsr_reg1_offs:
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.long (kvm_emulate_mtmsr_reg1 - kvm_emulate_mtmsr) / 4
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.global kvm_emulate_mtmsr_reg2_offs
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kvm_emulate_mtmsr_reg2_offs:
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.long (kvm_emulate_mtmsr_reg2 - kvm_emulate_mtmsr) / 4
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.global kvm_emulate_mtmsr_orig_ins_offs
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kvm_emulate_mtmsr_orig_ins_offs:
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.long (kvm_emulate_mtmsr_orig_ins - kvm_emulate_mtmsr) / 4
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.global kvm_emulate_mtmsr_len
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kvm_emulate_mtmsr_len:
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.long (kvm_emulate_mtmsr_end - kvm_emulate_mtmsr) / 4
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.global kvm_emulate_wrteei
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kvm_emulate_wrteei:
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SCRATCH_SAVE
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/* Fetch old MSR in r31 */
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LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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/* Remove MSR_EE from old MSR */
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li r30, 0
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ori r30, r30, MSR_EE
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andc r31, r31, r30
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/* OR new MSR_EE onto the old MSR */
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kvm_emulate_wrteei_ee:
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ori r31, r31, 0
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/* Write new MSR value back */
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STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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SCRATCH_RESTORE
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/* Go back to caller */
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kvm_emulate_wrteei_branch:
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b .
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kvm_emulate_wrteei_end:
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.global kvm_emulate_wrteei_branch_offs
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kvm_emulate_wrteei_branch_offs:
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.long (kvm_emulate_wrteei_branch - kvm_emulate_wrteei) / 4
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.global kvm_emulate_wrteei_ee_offs
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kvm_emulate_wrteei_ee_offs:
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.long (kvm_emulate_wrteei_ee - kvm_emulate_wrteei) / 4
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.global kvm_emulate_wrteei_len
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kvm_emulate_wrteei_len:
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.long (kvm_emulate_wrteei_end - kvm_emulate_wrteei) / 4
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.global kvm_emulate_mtsrin
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kvm_emulate_mtsrin:
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SCRATCH_SAVE
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LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
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andi. r31, r31, MSR_DR | MSR_IR
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beq kvm_emulate_mtsrin_reg1
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SCRATCH_RESTORE
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kvm_emulate_mtsrin_orig_ins:
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nop
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b kvm_emulate_mtsrin_branch
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kvm_emulate_mtsrin_reg1:
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/* rX >> 26 */
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rlwinm r30,r0,6,26,29
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kvm_emulate_mtsrin_reg2:
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stw r0, (KVM_MAGIC_PAGE + KVM_MAGIC_SR)(r30)
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SCRATCH_RESTORE
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/* Go back to caller */
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kvm_emulate_mtsrin_branch:
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b .
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kvm_emulate_mtsrin_end:
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.global kvm_emulate_mtsrin_branch_offs
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kvm_emulate_mtsrin_branch_offs:
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.long (kvm_emulate_mtsrin_branch - kvm_emulate_mtsrin) / 4
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.global kvm_emulate_mtsrin_reg1_offs
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kvm_emulate_mtsrin_reg1_offs:
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.long (kvm_emulate_mtsrin_reg1 - kvm_emulate_mtsrin) / 4
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.global kvm_emulate_mtsrin_reg2_offs
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kvm_emulate_mtsrin_reg2_offs:
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.long (kvm_emulate_mtsrin_reg2 - kvm_emulate_mtsrin) / 4
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.global kvm_emulate_mtsrin_orig_ins_offs
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kvm_emulate_mtsrin_orig_ins_offs:
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.long (kvm_emulate_mtsrin_orig_ins - kvm_emulate_mtsrin) / 4
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.global kvm_emulate_mtsrin_len
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kvm_emulate_mtsrin_len:
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.long (kvm_emulate_mtsrin_end - kvm_emulate_mtsrin) / 4
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