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Revision 95e16b4792b0429f1933872f743410f00e590c55 authored by Paolo Bonzini on 12 October 2021, 15:33:03 UTC, committed by Paolo Bonzini on 22 October 2021, 14:09:13 UTC 
KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if needed
 
The PIO scratch buffer is larger than a single page, and therefore
it is not possible to copy it in a single step to vcpu->arch/pio_data.
Bound each call to emulator_pio_in/out to a single page; keep
track of how many I/O operations are left in vcpu->arch.sev_pio_count,
so that the operation can be restarted in the complete_userspace_io
callback.

For OUT, this means that the previous kvm_sev_es_outs implementation
becomes an iterator of the loop, and we can consume the sev_pio_data
buffer before leaving to userspace.

For IN, instead, consuming the buffer and decreasing sev_pio_count
is always done in the complete_userspace_io callback, because that
is when the memcpy is done into sev_pio_data.

Cc: stable@vger.kernel.org
Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest")
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 parent 4fa4b38
Raw File
gup_test.h 
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __GUP_TEST_H
#define __GUP_TEST_H

#include <linux/types.h>

#define GUP_FAST_BENCHMARK	_IOWR('g', 1, struct gup_test)
#define PIN_FAST_BENCHMARK	_IOWR('g', 2, struct gup_test)
#define PIN_LONGTERM_BENCHMARK	_IOWR('g', 3, struct gup_test)
#define GUP_BASIC_TEST		_IOWR('g', 4, struct gup_test)
#define PIN_BASIC_TEST		_IOWR('g', 5, struct gup_test)
#define DUMP_USER_PAGES_TEST	_IOWR('g', 6, struct gup_test)

#define GUP_TEST_MAX_PAGES_TO_DUMP		8

#define GUP_TEST_FLAG_DUMP_PAGES_USE_PIN	0x1

struct gup_test {
	__u64 get_delta_usec;
	__u64 put_delta_usec;
	__u64 addr;
	__u64 size;
	__u32 nr_pages_per_call;
	__u32 gup_flags;
	__u32 test_flags;
	/*
	 * Each non-zero entry is the number of the page (1-based: first page is
	 * page 1, so that zero entries mean "do nothing") from the .addr base.
	 */
	__u32 which_pages[GUP_TEST_MAX_PAGES_TO_DUMP];
};

#endif	/* __GUP_TEST_H */
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