github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-28 17:13:52 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

x86/sev: Create a function to clear/zero the RMP

Browse Source 
In preparation for delayed SNP initialization and disablement on shutdown,
create a function, clear_rmp(), that clears the RMP bookkeeping area and the
RMP entries.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260324161301.1353976-2-tycho@kernel.org
This commit is contained in:
Tom Lendacky 2026-03-24 10:12:55 -06:00 committed by Borislav Petkov (AMD)
parent 531397a803
commit 9c016c3f49
1 changed files with 27 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
arch/x86/virt/svm/sev.c
View File

@ -242,6 +242,32 @@ void __init snp_fixup_e820_tables(void)
}
}
static void clear_rmp(void)
{
unsigned int i;
u64 val;
if (!cc_platform_has(CC_ATTR_HOST_SEV_SNP))
return;
/* Clearing the RMP while SNP is enabled will cause an exception */
rdmsrq(MSR_AMD64_SYSCFG, val);
if (WARN_ON_ONCE(val & MSR_AMD64_SYSCFG_SNP_EN))
return;
memset(rmp_bookkeeping, 0, RMPTABLE_CPU_BOOKKEEPING_SZ);
for (i = 0; i < rst_max_index; i++) {
struct rmp_segment_desc *desc;
desc = rmp_segment_table[i];
if (!desc)
continue;
memset(desc->rmp_entry, 0, desc->size);
}
}
static bool __init alloc_rmp_segment_desc(u64 segment_pa, u64 segment_size, u64 pa)
{
u64 rst_index, rmp_segment_size_max;
@ -484,7 +510,6 @@ static bool __init setup_rmptable(void)
*/
int __init snp_rmptable_init(void)
{
unsigned int i;
u64 val;
if (WARN_ON_ONCE(!cc_platform_has(CC_ATTR_HOST_SEV_SNP)))
@ -504,19 +529,7 @@ int __init snp_rmptable_init(void)
if (val & MSR_AMD64_SYSCFG_SNP_EN)
goto skip_enable;
/* Zero out the RMP bookkeeping area */
memset(rmp_bookkeeping, 0, RMPTABLE_CPU_BOOKKEEPING_SZ);
/* Zero out the RMP entries */
for (i = 0; i < rst_max_index; i++) {
struct rmp_segment_desc *desc;
desc = rmp_segment_table[i];
if (!desc)
continue;
memset(desc->rmp_entry, 0, desc->size);
}
clear_rmp();
/* MtrrFixDramModEn must be enabled on all the CPUs prior to enabling SNP. */
on_each_cpu(mfd_enable, NULL, 1);