6365ba64b4
KVM_HC_CLOCK_PAIRING currently fails inside SEV-SNP guests because the guest passes an address to static data to the host. In confidential computing the host can't access arbitrary guest memory so handling the hypercall runs into an "rmpfault". To make the hypercall work, the guest needs to explicitly mark the memory as decrypted. Do that in kvm_arch_ptp_init(), but retain the previous behavior for non-confidential guests to save us from having to allocate memory. Add a new arch-specific function (kvm_arch_ptp_exit()) to free the allocation and mark the memory as encrypted again. Signed-off-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com> Link: https://lore.kernel.org/r/20230308150531.477741-1-jpiotrowski@linux.microsoft.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
33 lines
567 B
C
33 lines
567 B
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Virtual PTP 1588 clock for use with KVM guests
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* Copyright (C) 2019 ARM Ltd.
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* All Rights Reserved
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*/
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#include <linux/arm-smccc.h>
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#include <linux/ptp_kvm.h>
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#include <asm/arch_timer.h>
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#include <asm/hypervisor.h>
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int kvm_arch_ptp_init(void)
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{
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int ret;
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ret = kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_PTP);
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if (ret <= 0)
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return -EOPNOTSUPP;
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return 0;
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}
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void kvm_arch_ptp_exit(void)
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{
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}
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int kvm_arch_ptp_get_clock(struct timespec64 *ts)
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{
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return kvm_arch_ptp_get_crosststamp(NULL, ts, NULL);
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}
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