https://github.com/torvalds/linux
Revision cff9211eb1a1f58ce7f5a2d596b617928fd4be0e authored by Christoffer Dall on 16 October 2015, 10:41:21 UTC, committed by Christoffer Dall on 20 October 2015, 16:04:54 UTC
We have an interesting issue when the guest disables the timer interrupt on the VGIC, which happens when turning VCPUs off using PSCI, for example. The problem is that because the guest disables the virtual interrupt at the VGIC level, we never inject interrupts to the guest and therefore never mark the interrupt as active on the physical distributor. The host also never takes the timer interrupt (we only use the timer device to trigger a guest exit and everything else is done in software), so the interrupt does not become active through normal means. The result is that we keep entering the guest with a programmed timer that will always fire as soon as we context switch the hardware timer state and run the guest, preventing forward progress for the VCPU. Since the active state on the physical distributor is really part of the timer logic, it is the job of our virtual arch timer driver to manage this state. The timer->map->active boolean field indicates whether we have signalled this interrupt to the vgic and if that interrupt is still pending or active. As long as that is the case, the hardware doesn't have to generate physical interrupts and therefore we mark the interrupt as active on the physical distributor. We also have to restore the pending state of an interrupt that was queued to an LR but was retired from the LR for some reason, while remaining pending in the LR. Cc: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
1 parent 4a5d69b
Tip revision: cff9211eb1a1f58ce7f5a2d596b617928fd4be0e authored by Christoffer Dall on 16 October 2015, 10:41:21 UTC
arm/arm64: KVM: Fix arch timer behavior for disabled interrupts
arm/arm64: KVM: Fix arch timer behavior for disabled interrupts
Tip revision: cff9211
eseqiv.c
/*
* eseqiv: Encrypted Sequence Number IV Generator
*
* This generator generates an IV based on a sequence number by xoring it
* with a salt and then encrypting it with the same key as used to encrypt
* the plain text. This algorithm requires that the block size be equal
* to the IV size. It is mainly useful for CBC.
*
* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/internal/skcipher.h>
#include <crypto/rng.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/spinlock.h>
#include <linux/string.h>
struct eseqiv_request_ctx {
struct scatterlist src[2];
struct scatterlist dst[2];
char tail[];
};
struct eseqiv_ctx {
spinlock_t lock;
unsigned int reqoff;
char salt[];
};
static void eseqiv_complete2(struct skcipher_givcrypt_request *req)
{
struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
struct eseqiv_request_ctx *reqctx = skcipher_givcrypt_reqctx(req);
memcpy(req->giv, PTR_ALIGN((u8 *)reqctx->tail,
crypto_ablkcipher_alignmask(geniv) + 1),
crypto_ablkcipher_ivsize(geniv));
}
static void eseqiv_complete(struct crypto_async_request *base, int err)
{
struct skcipher_givcrypt_request *req = base->data;
if (err)
goto out;
eseqiv_complete2(req);
out:
skcipher_givcrypt_complete(req, err);
}
static int eseqiv_givencrypt(struct skcipher_givcrypt_request *req)
{
struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
struct eseqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
struct eseqiv_request_ctx *reqctx = skcipher_givcrypt_reqctx(req);
struct ablkcipher_request *subreq;
crypto_completion_t compl;
void *data;
struct scatterlist *osrc, *odst;
struct scatterlist *dst;
struct page *srcp;
struct page *dstp;
u8 *giv;
u8 *vsrc;
u8 *vdst;
__be64 seq;
unsigned int ivsize;
unsigned int len;
int err;
subreq = (void *)(reqctx->tail + ctx->reqoff);
ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv));
giv = req->giv;
compl = req->creq.base.complete;
data = req->creq.base.data;
osrc = req->creq.src;
odst = req->creq.dst;
srcp = sg_page(osrc);
dstp = sg_page(odst);
vsrc = PageHighMem(srcp) ? NULL : page_address(srcp) + osrc->offset;
vdst = PageHighMem(dstp) ? NULL : page_address(dstp) + odst->offset;
ivsize = crypto_ablkcipher_ivsize(geniv);
if (vsrc != giv + ivsize && vdst != giv + ivsize) {
giv = PTR_ALIGN((u8 *)reqctx->tail,
crypto_ablkcipher_alignmask(geniv) + 1);
compl = eseqiv_complete;
data = req;
}
ablkcipher_request_set_callback(subreq, req->creq.base.flags, compl,
data);
sg_init_table(reqctx->src, 2);
sg_set_buf(reqctx->src, giv, ivsize);
scatterwalk_crypto_chain(reqctx->src, osrc, vsrc == giv + ivsize, 2);
dst = reqctx->src;
if (osrc != odst) {
sg_init_table(reqctx->dst, 2);
sg_set_buf(reqctx->dst, giv, ivsize);
scatterwalk_crypto_chain(reqctx->dst, odst, vdst == giv + ivsize, 2);
dst = reqctx->dst;
}
ablkcipher_request_set_crypt(subreq, reqctx->src, dst,
req->creq.nbytes + ivsize,
req->creq.info);
memcpy(req->creq.info, ctx->salt, ivsize);
len = ivsize;
if (ivsize > sizeof(u64)) {
memset(req->giv, 0, ivsize - sizeof(u64));
len = sizeof(u64);
}
seq = cpu_to_be64(req->seq);
memcpy(req->giv + ivsize - len, &seq, len);
err = crypto_ablkcipher_encrypt(subreq);
if (err)
goto out;
if (giv != req->giv)
eseqiv_complete2(req);
out:
return err;
}
static int eseqiv_init(struct crypto_tfm *tfm)
{
struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
struct eseqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
unsigned long alignmask;
unsigned int reqsize;
int err;
spin_lock_init(&ctx->lock);
alignmask = crypto_tfm_ctx_alignment() - 1;
reqsize = sizeof(struct eseqiv_request_ctx);
if (alignmask & reqsize) {
alignmask &= reqsize;
alignmask--;
}
alignmask = ~alignmask;
alignmask &= crypto_ablkcipher_alignmask(geniv);
reqsize += alignmask;
reqsize += crypto_ablkcipher_ivsize(geniv);
reqsize = ALIGN(reqsize, crypto_tfm_ctx_alignment());
ctx->reqoff = reqsize - sizeof(struct eseqiv_request_ctx);
tfm->crt_ablkcipher.reqsize = reqsize +
sizeof(struct ablkcipher_request);
err = 0;
if (!crypto_get_default_rng()) {
crypto_ablkcipher_crt(geniv)->givencrypt = eseqiv_givencrypt;
err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
crypto_ablkcipher_ivsize(geniv));
crypto_put_default_rng();
}
return err ?: skcipher_geniv_init(tfm);
}
static struct crypto_template eseqiv_tmpl;
static struct crypto_instance *eseqiv_alloc(struct rtattr **tb)
{
struct crypto_instance *inst;
int err;
inst = skcipher_geniv_alloc(&eseqiv_tmpl, tb, 0, 0);
if (IS_ERR(inst))
goto out;
err = -EINVAL;
if (inst->alg.cra_ablkcipher.ivsize != inst->alg.cra_blocksize)
goto free_inst;
inst->alg.cra_init = eseqiv_init;
inst->alg.cra_exit = skcipher_geniv_exit;
inst->alg.cra_ctxsize = sizeof(struct eseqiv_ctx);
inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize;
out:
return inst;
free_inst:
skcipher_geniv_free(inst);
inst = ERR_PTR(err);
goto out;
}
static struct crypto_template eseqiv_tmpl = {
.name = "eseqiv",
.alloc = eseqiv_alloc,
.free = skcipher_geniv_free,
.module = THIS_MODULE,
};
static int __init eseqiv_module_init(void)
{
return crypto_register_template(&eseqiv_tmpl);
}
static void __exit eseqiv_module_exit(void)
{
crypto_unregister_template(&eseqiv_tmpl);
}
module_init(eseqiv_module_init);
module_exit(eseqiv_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Encrypted Sequence Number IV Generator");
MODULE_ALIAS_CRYPTO("eseqiv");
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