diff options
author | Tianyu Lan <tiala@microsoft.com> | 2023-08-18 13:29:14 +0300 |
---|---|---|
committer | Wei Liu <wei.liu@kernel.org> | 2023-08-22 03:38:20 +0300 |
commit | 193061ea0a50c13f72b907e6fa7befa6e15a4302 (patch) | |
tree | f214cd173c276e2ba2ea09dec06117ae84a1c042 | |
parent | b13103559dddbc64330c2e63ebf7342e70fbab4e (diff) | |
download | linux-193061ea0a50c13f72b907e6fa7befa6e15a4302.tar.xz |
drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest
Hypervisor needs to access input arg, VMBus synic event and
message pages. Mark these pages unencrypted in the SEV-SNP
guest and free them only if they have been marked encrypted
successfully.
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230818102919.1318039-5-ltykernel@gmail.com
-rw-r--r-- | drivers/hv/hv.c | 57 | ||||
-rw-r--r-- | drivers/hv/hv_common.c | 13 |
2 files changed, 67 insertions, 3 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index de6708dbe0df..ec6e35a0d9bf 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -20,6 +20,7 @@ #include <linux/interrupt.h> #include <clocksource/hyperv_timer.h> #include <asm/mshyperv.h> +#include <linux/set_memory.h> #include "hyperv_vmbus.h" /* The one and only */ @@ -78,7 +79,7 @@ int hv_post_message(union hv_connection_id connection_id, int hv_synic_alloc(void) { - int cpu; + int cpu, ret = -ENOMEM; struct hv_per_cpu_context *hv_cpu; /* @@ -123,26 +124,76 @@ int hv_synic_alloc(void) goto err; } } + + if (hv_isolation_type_en_snp()) { + ret = set_memory_decrypted((unsigned long) + hv_cpu->synic_message_page, 1); + if (ret) { + pr_err("Failed to decrypt SYNIC msg page: %d\n", ret); + hv_cpu->synic_message_page = NULL; + + /* + * Free the event page here so that hv_synic_free() + * won't later try to re-encrypt it. + */ + free_page((unsigned long)hv_cpu->synic_event_page); + hv_cpu->synic_event_page = NULL; + goto err; + } + + ret = set_memory_decrypted((unsigned long) + hv_cpu->synic_event_page, 1); + if (ret) { + pr_err("Failed to decrypt SYNIC event page: %d\n", ret); + hv_cpu->synic_event_page = NULL; + goto err; + } + + memset(hv_cpu->synic_message_page, 0, PAGE_SIZE); + memset(hv_cpu->synic_event_page, 0, PAGE_SIZE); + } } return 0; + err: /* * Any memory allocations that succeeded will be freed when * the caller cleans up by calling hv_synic_free() */ - return -ENOMEM; + return ret; } void hv_synic_free(void) { - int cpu; + int cpu, ret; for_each_present_cpu(cpu) { struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); + /* It's better to leak the page if the encryption fails. */ + if (hv_isolation_type_en_snp()) { + if (hv_cpu->synic_message_page) { + ret = set_memory_encrypted((unsigned long) + hv_cpu->synic_message_page, 1); + if (ret) { + pr_err("Failed to encrypt SYNIC msg page: %d\n", ret); + hv_cpu->synic_message_page = NULL; + } + } + + if (hv_cpu->synic_event_page) { + ret = set_memory_encrypted((unsigned long) + hv_cpu->synic_event_page, 1); + if (ret) { + pr_err("Failed to encrypt SYNIC event page: %d\n", ret); + hv_cpu->synic_event_page = NULL; + } + } + } + free_page((unsigned long)hv_cpu->synic_event_page); free_page((unsigned long)hv_cpu->synic_message_page); } diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index 4b4aa53c34c2..2d43ba2bc925 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -24,6 +24,7 @@ #include <linux/kmsg_dump.h> #include <linux/slab.h> #include <linux/dma-map-ops.h> +#include <linux/set_memory.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h> @@ -359,6 +360,7 @@ int hv_common_cpu_init(unsigned int cpu) u64 msr_vp_index; gfp_t flags; int pgcount = hv_root_partition ? 2 : 1; + int ret; /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */ flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL; @@ -378,6 +380,17 @@ int hv_common_cpu_init(unsigned int cpu) outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg); *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE; } + + if (hv_isolation_type_en_snp()) { + ret = set_memory_decrypted((unsigned long)*inputarg, pgcount); + if (ret) { + kfree(*inputarg); + *inputarg = NULL; + return ret; + } + + memset(*inputarg, 0x00, pgcount * PAGE_SIZE); + } } msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX); |